Fannie  Zemlak

Fannie Zemlak

1602266400

How to Make Pure SwiftUI Keyboard Toolbar?

Xcode 12 — iOS 14

Image for post

In this tutorial we are going to implement a keyboard wrapper view. This view at root level can show/hide custom keyboard toolbar and manage view hight.

Steps:

  • Create a generic view which takes content and toolbar view callbacks as parameter.
struct KeyboardView<Content, ToolBar> : View where Content : View, ToolBar: View {

 @StateObject private var keyboard: KeyboardResponder = KeyboardResponder()
 let toolbarFrame: CGSize = CGSize(width: UIScreen.main.bounds.width, height: 40.0)
 var content: () -> Content
 var toolBar: () -> ToolBar
 var body: some View {
  //to do 
 }

}
  • Create a Keyboard observer(picked from here):
	struct KeyboardView<Content, ToolBar> : View where Content : View, ToolBar: View {
	    @StateObject private var keyboard: KeyboardResponder = KeyboardResponder()
	    let toolbarFrame: CGSize = CGSize(width: UIScreen.main.bounds.width, height: 40.0)
	    var content: () -> Content
	    var toolBar: () -> ToolBar

	    var body: some View {
	        ZStack {
	            content()
	                .padding(.bottom, (keyboard.currentHeight == 0) ? 0 : toolbarFrame.height)
	            VStack {
	                 Spacer()
	                 toolBar()
	                    .frame(width: toolbarFrame.width, height: toolbarFrame.height)
	                    .background(Color.secondary)
	            }.opacity((keyboard.currentHeight == 0) ? 0 : 1)
	            .animation(.easeOut)
	        }
	        .padding(.bottom, keyboard.currentHeight)
	        .edgesIgnoringSafeArea(.bottom)
	        .animation(.easeOut)

	    }
	}

#programming #swiftui #swift #keyboard #toolbar

What is GEEK

Buddha Community

How to Make Pure SwiftUI Keyboard Toolbar?
Fannie  Zemlak

Fannie Zemlak

1602266400

How to Make Pure SwiftUI Keyboard Toolbar?

Xcode 12 — iOS 14

Image for post

In this tutorial we are going to implement a keyboard wrapper view. This view at root level can show/hide custom keyboard toolbar and manage view hight.

Steps:

  • Create a generic view which takes content and toolbar view callbacks as parameter.
struct KeyboardView<Content, ToolBar> : View where Content : View, ToolBar: View {

 @StateObject private var keyboard: KeyboardResponder = KeyboardResponder()
 let toolbarFrame: CGSize = CGSize(width: UIScreen.main.bounds.width, height: 40.0)
 var content: () -> Content
 var toolBar: () -> ToolBar
 var body: some View {
  //to do 
 }

}
  • Create a Keyboard observer(picked from here):
	struct KeyboardView<Content, ToolBar> : View where Content : View, ToolBar: View {
	    @StateObject private var keyboard: KeyboardResponder = KeyboardResponder()
	    let toolbarFrame: CGSize = CGSize(width: UIScreen.main.bounds.width, height: 40.0)
	    var content: () -> Content
	    var toolBar: () -> ToolBar

	    var body: some View {
	        ZStack {
	            content()
	                .padding(.bottom, (keyboard.currentHeight == 0) ? 0 : toolbarFrame.height)
	            VStack {
	                 Spacer()
	                 toolBar()
	                    .frame(width: toolbarFrame.width, height: toolbarFrame.height)
	                    .background(Color.secondary)
	            }.opacity((keyboard.currentHeight == 0) ? 0 : 1)
	            .animation(.easeOut)
	        }
	        .padding(.bottom, keyboard.currentHeight)
	        .edgesIgnoringSafeArea(.bottom)
	        .animation(.easeOut)

	    }
	}

#programming #swiftui #swift #keyboard #toolbar

Elian  Harber

Elian Harber

1641430440

Bokeh Plotting Backend for Pandas and GeoPandas

Pandas-Bokeh provides a Bokeh plotting backend for Pandas, GeoPandas and Pyspark DataFrames, similar to the already existing Visualization feature of Pandas. Importing the library adds a complementary plotting method plot_bokeh() on DataFrames and Series.

With Pandas-Bokeh, creating stunning, interactive, HTML-based visualization is as easy as calling:

df.plot_bokeh()

Pandas-Bokeh also provides native support as a Pandas Plotting backend for Pandas >= 0.25. When Pandas-Bokeh is installed, switchting the default Pandas plotting backend to Bokeh can be done via:

pd.set_option('plotting.backend', 'pandas_bokeh')

More details about the new Pandas backend can be found below.


Interactive Documentation

Please visit:

https://patrikhlobil.github.io/Pandas-Bokeh/

for an interactive version of the documentation below, where you can play with the dynamic Bokeh plots.


For more information have a look at the Examples below or at notebooks on the Github Repository of this project.

Startimage


 

Installation

You can install Pandas-Bokeh from PyPI via pip

pip install pandas-bokeh

or conda:

conda install -c patrikhlobil pandas-bokeh

With the current release 0.5.5, Pandas-Bokeh officially supports Python 3.6 and newer. For more details, see Release Notes.

How To Use

Classical Use

The Pandas-Bokeh library should be imported after Pandas, GeoPandas and/or Pyspark. After the import, one should define the plotting output, which can be:

pandas_bokeh.output_notebook(): Embeds the Plots in the cell outputs of the notebook. Ideal when working in Jupyter Notebooks.

pandas_bokeh.output_file(filename): Exports the plot to the provided filename as an HTML.

For more details about the plotting outputs, see the reference here or the Bokeh documentation.

Notebook output (see also bokeh.io.output_notebook)

import pandas as pd import pandas_bokeh pandas_bokeh.output_notebook()

File output to "Interactive Plot.html" (see also bokeh.io.output_file)

import pandas as pd import pandas_bokeh pandas_bokeh.output_file("Interactive Plot.html")

Pandas-Bokeh as native Pandas plotting backend

For pandas >= 0.25, a plotting backend switch is natively supported. It can be achievied by calling:

import pandas as pd
pd.set_option('plotting.backend', 'pandas_bokeh')

Now, the plotting API is accessible for a Pandas DataFrame via:

df.plot(...)

All additional functionalities of Pandas-Bokeh are then accessible at pd.plotting. So, setting the output to notebook is:

pd.plotting.output_notebook()

or calling the grid layout functionality:

pd.plotting.plot_grid(...)

Note: Backwards compatibility is kept since there will still be the df.plot_bokeh(...) methods for a DataFrame.


Plot types

Supported plottypes are at the moment:

Also, check out the complementary chapter Outputs, Formatting & Layouts about:


Lineplot

Basic Lineplot

This simple lineplot in Pandas-Bokeh already contains various interactive elements:

  • a pannable and zoomable (zoom in plotarea and zoom on axis) plot
  • by clicking on the legend elements, one can hide and show the individual lines
  • a Hovertool for the plotted lines

Consider the following simple example:

import numpy as np

np.random.seed(42)
df = pd.DataFrame({"Google": np.random.randn(1000)+0.2, 
                   "Apple": np.random.randn(1000)+0.17}, 
                   index=pd.date_range('1/1/2000', periods=1000))
df = df.cumsum()
df = df + 50
df.plot_bokeh(kind="line")       #equivalent to df.plot_bokeh.line()

ApplevsGoogle_1

Note, that similar to the regular pandas.DataFrame.plot method, there are also additional accessors to directly access the different plotting types like:

  • df.plot_bokeh(kind="line", ...)df.plot_bokeh.line(...)
  • df.plot_bokeh(kind="bar", ...)df.plot_bokeh.bar(...)
  • df.plot_bokeh(kind="hist", ...)df.plot_bokeh.hist(...)
  • ...

Advanced Lineplot

There are various optional parameters to tune the plots, for example:

kind: Which kind of plot should be produced. Currently supported are: "line", "point", "scatter", "bar" and "histogram". In the near future many more will be implemented as horizontal barplot, boxplots, pie-charts, etc.

x: Name of the column to use for the horizontal x-axis. If the x parameter is not specified, the index is used for the x-values of the plot. Alternative, also an array of values can be passed that has the same number of elements as the DataFrame.

y: Name of column or list of names of columns to use for the vertical y-axis.

figsize: Choose width & height of the plot

title: Sets title of the plot

xlim/ylim: Set visibler range of plot for x- and y-axis (also works for datetime x-axis)

xlabel/ylabel: Set x- and y-labels

logx/logy: Set log-scale on x-/y-axis

xticks/yticks: Explicitly set the ticks on the axes

color: Defines a single color for a plot.

colormap: Can be used to specify multiple colors to plot. Can be either a list of colors or the name of a Bokeh color palette

hovertool: If True a Hovertool is active, else if False no Hovertool is drawn.

hovertool_string: If specified, this string will be used for the hovertool (@{column} will be replaced by the value of the column for the element the mouse hovers over, see also Bokeh documentation and here)

toolbar_location: Specify the position of the toolbar location (None, "above", "below", "left" or "right"). Default: "right"

zooming: Enables/Disables zooming. Default: True

panning: Enables/Disables panning. Default: True

fontsize_label/fontsize_ticks/fontsize_title/fontsize_legend: Set fontsize of labels, ticks, title or legend (int or string of form "15pt")

rangetool Enables a range tool scroller. Default False

kwargs**: Optional keyword arguments of bokeh.plotting.figure.line

Try them out to get a feeling for the effects. Let us consider now:

df.plot_bokeh.line(
    figsize=(800, 450),
    y="Apple",
    title="Apple vs Google",
    xlabel="Date",
    ylabel="Stock price [$]",
    yticks=[0, 100, 200, 300, 400],
    ylim=(0, 400),
    toolbar_location=None,
    colormap=["red", "blue"],
    hovertool_string=r"""<img
                        src='https://upload.wikimedia.org/wikipedia/commons/thumb/f/fa/Apple_logo_black.svg/170px-Apple_logo_black.svg.png' 
                        height="42" alt="@imgs" width="42"
                        style="float: left; margin: 0px 15px 15px 0px;"
                        border="2"></img> Apple 
                        
                        <h4> Stock Price: </h4> @{Apple}""",
    panning=False,
    zooming=False)

ApplevsGoogle_2

Lineplot with data points

For lineplots, as for many other plot-kinds, there are some special keyword arguments that only work for this plotting type. For lineplots, these are:

plot_data_points: Plot also the data points on the lines

plot_data_points_size: Determines the size of the data points

marker: Defines the point type (Default: "circle"). Possible values are: 'circle', 'square', 'triangle', 'asterisk', 'circle_x', 'square_x', 'inverted_triangle', 'x', 'circle_cross', 'square_cross', 'diamond', 'cross'

kwargs**: Optional keyword arguments of bokeh.plotting.figure.line```

Let us use this information to have another version of the same plot:

df.plot_bokeh.line(
    figsize=(800, 450),
    title="Apple vs Google",
    xlabel="Date",
    ylabel="Stock price [$]",
    yticks=[0, 100, 200, 300, 400],
    ylim=(100, 200),
    xlim=("2001-01-01", "2001-02-01"),
    colormap=["red", "blue"],
    plot_data_points=True,
    plot_data_points_size=10,
    marker="asterisk")

ApplevsGoogle_3

Lineplot with rangetool

ts = pd.Series(np.random.randn(1000), index=pd.date_range('1/1/2000', periods=1000))
df = pd.DataFrame(np.random.randn(1000, 4), index=ts.index, columns=list('ABCD'))
df = df.cumsum()

df.plot_bokeh(rangetool=True)

rangetool

Pointplot

If you just wish to draw the date points for curves, the pointplot option is the right choice. It also accepts the kwargs of bokeh.plotting.figure.scatter like marker or size:

import numpy as np

x = np.arange(-3, 3, 0.1)
y2 = x**2
y3 = x**3
df = pd.DataFrame({"x": x, "Parabula": y2, "Cube": y3})
df.plot_bokeh.point(
    x="x",
    xticks=range(-3, 4),
    size=5,
    colormap=["#009933", "#ff3399"],
    title="Pointplot (Parabula vs. Cube)",
    marker="x")

Pointplot

Stepplot

With a similar API as the line- & pointplots, one can generate a stepplot. Additional keyword arguments for this plot type are passes to bokeh.plotting.figure.step, e.g. mode (before, after, center), see the following example

import numpy as np

x = np.arange(-3, 3, 1)
y2 = x**2
y3 = x**3
df = pd.DataFrame({"x": x, "Parabula": y2, "Cube": y3})
df.plot_bokeh.step(
    x="x",
    xticks=range(-1, 1),
    colormap=["#009933", "#ff3399"],
    title="Pointplot (Parabula vs. Cube)",
    figsize=(800,300),
    fontsize_title=30,
    fontsize_label=25,
    fontsize_ticks=15,
    fontsize_legend=5,
    )

df.plot_bokeh.step(
    x="x",
    xticks=range(-1, 1),
    colormap=["#009933", "#ff3399"],
    title="Pointplot (Parabula vs. Cube)",
    mode="after",
    figsize=(800,300)
    )

Stepplot

Note that the step-plot API of Bokeh does so far not support a hovertool functionality.

Scatterplot

A basic scatterplot can be created using the kind="scatter" option. For scatterplots, the x and y parameters have to be specified and the following optional keyword argument is allowed:

category: Determines the category column to use for coloring the scatter points

kwargs**: Optional keyword arguments of bokeh.plotting.figure.scatter

Note, that the pandas.DataFrame.plot_bokeh() method return per default a Bokeh figure, which can be embedded in Dashboard layouts with other figures and Bokeh objects (for more details about (sub)plot layouts and embedding the resulting Bokeh plots as HTML click here).

In the example below, we use the building grid layout support of Pandas-Bokeh to display both the DataFrame (using a Bokeh DataTable) and the resulting scatterplot:

# Load Iris Dataset:
df = pd.read_csv(
    r"https://raw.githubusercontent.com/PatrikHlobil/Pandas-Bokeh/master/docs/Testdata/iris/iris.csv"
)
df = df.sample(frac=1)

# Create Bokeh-Table with DataFrame:
from bokeh.models.widgets import DataTable, TableColumn
from bokeh.models import ColumnDataSource

data_table = DataTable(
    columns=[TableColumn(field=Ci, title=Ci) for Ci in df.columns],
    source=ColumnDataSource(df),
    height=300,
)

# Create Scatterplot:
p_scatter = df.plot_bokeh.scatter(
    x="petal length (cm)",
    y="sepal width (cm)",
    category="species",
    title="Iris DataSet Visualization",
    show_figure=False,
)

# Combine Table and Scatterplot via grid layout:
pandas_bokeh.plot_grid([[data_table, p_scatter]], plot_width=400, plot_height=350)

 

Scatterplot

A possible optional keyword parameters that can be passed to bokeh.plotting.figure.scatter is size. Below, we use the sepal length of the Iris data as reference for the size:

#Change one value to clearly see the effect of the size keyword
df.loc[13, "sepal length (cm)"] = 15

#Make scatterplot:
p_scatter = df.plot_bokeh.scatter(
    x="petal length (cm)",
    y="sepal width (cm)",
    category="species",
    title="Iris DataSet Visualization with Size Keyword",
    size="sepal length (cm)")

Scatterplot2

In this example you can see, that the additional dimension sepal length cannot be used to clearly differentiate between the virginica and versicolor species.

Barplot

The barplot API has no special keyword arguments, but accepts optional kwargs of bokeh.plotting.figure.vbar like alpha. It uses per default the index for the bar categories (however, also columns can be used as x-axis category using the x argument).

data = {
    'fruits':
    ['Apples', 'Pears', 'Nectarines', 'Plums', 'Grapes', 'Strawberries'],
    '2015': [2, 1, 4, 3, 2, 4],
    '2016': [5, 3, 3, 2, 4, 6],
    '2017': [3, 2, 4, 4, 5, 3]
}
df = pd.DataFrame(data).set_index("fruits")

p_bar = df.plot_bokeh.bar(
    ylabel="Price per Unit [€]", 
    title="Fruit prices per Year", 
    alpha=0.6)

Barplot

Using the stacked keyword argument you also maked stacked barplots:

p_stacked_bar = df.plot_bokeh.bar(
    ylabel="Price per Unit [€]",
    title="Fruit prices per Year",
    stacked=True,
    alpha=0.6)

Barplot2

Also horizontal versions of the above barplot are supported with the keyword kind="barh" or the accessor plot_bokeh.barh. You can still specify a column of the DataFrame as the bar category via the x argument if you do not wish to use the index.

#Reset index, such that "fruits" is now a column of the DataFrame:
df.reset_index(inplace=True)

#Create horizontal bar (via kind keyword):
p_hbar = df.plot_bokeh(
    kind="barh",
    x="fruits",
    xlabel="Price per Unit [€]",
    title="Fruit prices per Year",
    alpha=0.6,
    legend = "bottom_right",
    show_figure=False)

#Create stacked horizontal bar (via barh accessor):
p_stacked_hbar = df.plot_bokeh.barh(
    x="fruits",
    stacked=True,
    xlabel="Price per Unit [€]",
    title="Fruit prices per Year",
    alpha=0.6,
    legend = "bottom_right",
    show_figure=False)

#Plot all barplot examples in a grid:
pandas_bokeh.plot_grid([[p_bar, p_stacked_bar],
                        [p_hbar, p_stacked_hbar]], 
                       plot_width=450)

Barplot3

Histogram

For drawing histograms (kind="hist"), Pandas-Bokeh has a lot of customization features. Optional keyword arguments for histogram plots are:

bins: Determines bins to use for the histogram. If bins is an int, it defines the number of equal-width bins in the given range (10, by default). If bins is a sequence, it defines the bin edges, including the rightmost edge, allowing for non-uniform bin widths. If bins is a string, it defines the method used to calculate the optimal bin width, as defined by histogram_bin_edges.

histogram_type: Either "sidebyside", "topontop" or "stacked". Default: "topontop"

stacked: Boolean that overrides the histogram_type as "stacked" if given. Default: False

kwargs**: Optional keyword arguments of bokeh.plotting.figure.quad

Below examples of the different histogram types:

import numpy as np

df_hist = pd.DataFrame({
    'a': np.random.randn(1000) + 1,
    'b': np.random.randn(1000),
    'c': np.random.randn(1000) - 1
    },
    columns=['a', 'b', 'c'])

#Top-on-Top Histogram (Default):
df_hist.plot_bokeh.hist(
    bins=np.linspace(-5, 5, 41),
    vertical_xlabel=True,
    hovertool=False,
    title="Normal distributions (Top-on-Top)",
    line_color="black")

#Side-by-Side Histogram (multiple bars share bin side-by-side) also accessible via
#kind="hist":
df_hist.plot_bokeh(
    kind="hist",
    bins=np.linspace(-5, 5, 41),
    histogram_type="sidebyside",
    vertical_xlabel=True,
    hovertool=False,
    title="Normal distributions (Side-by-Side)",
    line_color="black")

#Stacked histogram:
df_hist.plot_bokeh.hist(
    bins=np.linspace(-5, 5, 41),
    histogram_type="stacked",
    vertical_xlabel=True,
    hovertool=False,
    title="Normal distributions (Stacked)",
    line_color="black")

Histogram

Further, advanced keyword arguments for histograms are:

  • weights: A column of the DataFrame that is used as weight for the histogramm aggregation (see also numpy.histogram)
  • normed: If True, histogram values are normed to 1 (sum of histogram values=1). It is also possible to pass an integer, e.g. normed=100 would result in a histogram with percentage y-axis (sum of histogram values=100). Default: False
  • cumulative: If True, a cumulative histogram is shown. Default: False
  • show_average: If True, the average of the histogram is also shown. Default: False

Their usage is shown in these examples:

p_hist = df_hist.plot_bokeh.hist(
    y=["a", "b"],
    bins=np.arange(-4, 6.5, 0.5),
    normed=100,
    vertical_xlabel=True,
    ylabel="Share[%]",
    title="Normal distributions (normed)",
    show_average=True,
    xlim=(-4, 6),
    ylim=(0, 30),
    show_figure=False)

p_hist_cum = df_hist.plot_bokeh.hist(
    y=["a", "b"],
    bins=np.arange(-4, 6.5, 0.5),
    normed=100,
    cumulative=True,
    vertical_xlabel=True,
    ylabel="Share[%]",
    title="Normal distributions (normed & cumulative)",
    show_figure=False)

pandas_bokeh.plot_grid([[p_hist, p_hist_cum]], plot_width=450, plot_height=300)

Histogram2


 

Areaplot

Areaplot (kind="area") can be either drawn on top of each other or stacked. The important parameters are:

stacked: If True, the areaplots are stacked. If False, plots are drawn on top of each other. Default: False

kwargs**: Optional keyword arguments of bokeh.plotting.figure.patch


Let us consider the energy consumption split by source that can be downloaded as DataFrame via:

df_energy = pd.read_csv(r"https://raw.githubusercontent.com/PatrikHlobil/Pandas-Bokeh/master/docs/Testdata/energy/energy.csv", 
parse_dates=["Year"])
df_energy.head()
YearOilGasCoalNuclear EnergyHydroelectricityOther Renewable
1970-01-012291.5826.71467.317.7265.85.8
1971-01-012427.7884.81459.224.9276.46.3
1972-01-012613.9933.71475.734.1288.96.8
1973-01-012818.1978.01519.645.9292.57.3
1974-01-012777.31001.91520.959.6321.17.7


Creating the Areaplot can be achieved via:

df_energy.plot_bokeh.area(
    x="Year",
    stacked=True,
    legend="top_left",
    colormap=["brown", "orange", "black", "grey", "blue", "green"],
    title="Worldwide energy consumption split by energy source",
    ylabel="Million tonnes oil equivalent",
    ylim=(0, 16000))

areaplot

Note that the energy consumption of fossile energy is still increasing and renewable energy sources are still small in comparison 😢!!! However, when we norm the plot using the normed keyword, there is a clear trend towards renewable energies in the last decade:

df_energy.plot_bokeh.area(
    x="Year",
    stacked=True,
    normed=100,
    legend="bottom_left",
    colormap=["brown", "orange", "black", "grey", "blue", "green"],
    title="Worldwide energy consumption split by energy source",
    ylabel="Million tonnes oil equivalent")

areaplot2

Pieplot

For Pieplots, let us consider a dataset showing the results of all Bundestags elections in Germany since 2002:

df_pie = pd.read_csv(r"https://raw.githubusercontent.com/PatrikHlobil/Pandas-Bokeh/master/docs/Testdata/Bundestagswahl/Bundestagswahl.csv")
df_pie
Partei20022005200920132017
CDU/CSU38.535.233.841.532.9
SPD38.534.223.025.720.5
FDP7.49.814.64.810.7
Grünen8.68.110.78.48.9
Linke/PDS4.08.711.98.69.2
AfD0.00.00.00.012.6
Sonstige3.04.06.011.05.0

We can create a Pieplot of the last election in 2017 by specifying the "Partei" (german for party) column as the x column and the "2017" column as the y column for values:

df_pie.plot_bokeh.pie(
    x="Partei",
    y="2017",
    colormap=["blue", "red", "yellow", "green", "purple", "orange", "grey"],
    title="Results of German Bundestag Election 2017",
    )

pieplot

When you pass several columns to the y parameter (not providing the y-parameter assumes you plot all columns), multiple nested pieplots will be shown in one plot:

df_pie.plot_bokeh.pie(
    x="Partei",
    colormap=["blue", "red", "yellow", "green", "purple", "orange", "grey"],
    title="Results of German Bundestag Elections [2002-2017]",
    line_color="grey")

pieplot2

Mapplot

The mapplot method of Pandas-Bokeh allows for plotting geographic points stored in a Pandas DataFrame on an interactive map. For more advanced Geoplots for line and polygon shapes have a look at the Geoplots examples for the GeoPandas API of Pandas-Bokeh.

For mapplots, only (latitude, longitude) pairs in geographic projection (WGS84) can be plotted on a map. The basic API has the following 2 base parameters:

  • x: name of the longitude column of the DataFrame
  • y: name of the latitude column of the DataFrame

The other optional keyword arguments are discussed in the section about the GeoPandas API, e.g. category for coloring the points.

Below an example of plotting all cities for more than 1 million inhabitants:

df_mapplot = pd.read_csv(r"https://raw.githubusercontent.com/PatrikHlobil/Pandas-Bokeh/master/docs/Testdata/populated%20places/populated_places.csv")
df_mapplot.head()
namepop_maxlatitudelongitudesize
Mesa108539433.423915-111.7360841.085394
Sharjah110302725.37138355.4064781.103027
Changwon108149935.219102128.5835621.081499
Sheffield129290053.366677-1.4999971.292900
Abbottabad118364734.14950373.1995011.183647
df_mapplot["size"] = df_mapplot["pop_max"] / 1000000
df_mapplot.plot_bokeh.map(
    x="longitude",
    y="latitude",
    hovertool_string="""<h2> @{name} </h2> 
    
                        <h3> Population: @{pop_max} </h3>""",
    tile_provider="STAMEN_TERRAIN_RETINA",
    size="size", 
    figsize=(900, 600),
    title="World cities with more than 1.000.000 inhabitants")

 

Mapplot

Geoplots

Pandas-Bokeh also allows for interactive plotting of Maps using GeoPandas by providing a geopandas.GeoDataFrame.plot_bokeh() method. It allows to plot the following geodata on a map :

  • Points/MultiPoints
  • Lines/MultiLines
  • Polygons/MultiPolygons

Note: t is not possible to mix up the objects types, i.e. a GeoDataFrame with Points and Lines is for example not allowed.

Les us start with a simple example using the "World Borders Dataset" . Let us first import all neccessary libraries and read the shapefile:

import geopandas as gpd
import pandas as pd
import pandas_bokeh
pandas_bokeh.output_notebook()

#Read in GeoJSON from URL:
df_states = gpd.read_file(r"https://raw.githubusercontent.com/PatrikHlobil/Pandas-Bokeh/master/docs/Testdata/states/states.geojson")
df_states.head()
STATE_NAMEREGIONPOPESTIMATE2010POPESTIMATE2011POPESTIMATE2012POPESTIMATE2013POPESTIMATE2014POPESTIMATE2015POPESTIMATE2016POPESTIMATE2017geometry
Hawaii413638171378323139277214080381417710142632014286831427538(POLYGON ((-160.0738033454681 22.0041773479577...
Washington467413866819155689089969634107046931715281872809347405743(POLYGON ((-122.4020153103835 48.2252163723779...
Montana4990507996866100352210119211019931102831710386561050493POLYGON ((-111.4754253002074 44.70216236909688...
Maine113275681327968132810113279751328903132778713302321335907(POLYGON ((-69.77727626137293 44.0741483685119...
North Dakota2674518684830701380722908738658754859755548755393POLYGON ((-98.73043728833767 45.93827137024809...

Plotting the data on a map is as simple as calling:

df_states.plot_bokeh(simplify_shapes=10000)

US_States_1

We also passed the optional parameter simplify_shapes (~meter) to improve plotting performance (for a reference see shapely.object.simplify). The above geolayer thus has an accuracy of about 10km.

Many keyword arguments like xlabel, ylabel, xlim, ylim, title, colormap, hovertool, zooming, panning, ... for costumizing the plot are also available for the geoplotting API and can be uses as in the examples shown above. There are however also many other options especially for plotting geodata:

  • geometry_column: Specify the column that stores the geometry-information (default: "geometry")
  • hovertool_columns: Specify column names, for which values should be shown in hovertool
  • hovertool_string: If specified, this string will be used for the hovertool (@{column} will be replaced by the value of the column for the element the mouse hovers over, see also Bokeh documentation)
  • colormap_uselog: If set True, the colormapper is using a logscale. Default: False
  • colormap_range: Specify the value range of the colormapper via (min, max) tuple
  • tile_provider: Define build-in tile provider for background maps. Possible values: None, 'CARTODBPOSITRON', 'CARTODBPOSITRON_RETINA', 'STAMEN_TERRAIN', 'STAMEN_TERRAIN_RETINA', 'STAMEN_TONER', 'STAMEN_TONER_BACKGROUND', 'STAMEN_TONER_LABELS'. Default: CARTODBPOSITRON_RETINA
  • tile_provider_url: An arbitraty tile_provider_url of the form '/{Z}/{X}/{Y}*.png' can be passed to be used as background map.
  • tile_attribution: String (also HTML accepted) for showing attribution for tile source in the lower right corner
  • tile_alpha: Sets the alpha value of the background tile between [0, 1]. Default: 1

One of the most common usage of map plots are choropleth maps, where the color of a the objects is determined by the property of the object itself. There are 3 ways of drawing choropleth maps using Pandas-Bokeh, which are described below.

Categories

This is the simplest way. Just provide the category keyword for the selection of the property column:

  • category: Specifies the column of the GeoDataFrame that should be used to draw a choropleth map
  • show_colorbar: Whether or not to show a colorbar for categorical plots. Default: True

Let us now draw the regions as a choropleth plot using the category keyword (at the moment, only numerical columns are supported for choropleth plots):

df_states.plot_bokeh(
    figsize=(900, 600),
    simplify_shapes=5000,
    category="REGION",
    show_colorbar=False,
    colormap=["blue", "yellow", "green", "red"],
    hovertool_columns=["STATE_NAME", "REGION"],
    tile_provider="STAMEN_TERRAIN_RETINA")

When hovering over the states, the state-name and the region are shown as specified in the hovertool_columns argument.

US_States_2

 

Dropdown

By passing a list of column names of the GeoDataFrame as the dropdown keyword argument, a dropdown menu is shown above the map. This dropdown menu can be used to select the choropleth layer by the user. :

df_states["STATE_NAME_SMALL"] = df_states["STATE_NAME"].str.lower()

df_states.plot_bokeh(
    figsize=(900, 600),
    simplify_shapes=5000,
    dropdown=["POPESTIMATE2010", "POPESTIMATE2017"],
    colormap="Viridis",
    hovertool_string="""
                        <img
                        src="https://www.states101.com/img/flags/gif/small/@STATE_NAME_SMALL.gif" 
                        height="42" alt="@imgs" width="42"
                        style="float: left; margin: 0px 15px 15px 0px;"
                        border="2"></img>
                
                        <h2>  @STATE_NAME </h2>
                        <h3> 2010: @POPESTIMATE2010 </h3>
                        <h3> 2017: @POPESTIMATE2017 </h3>""",
    tile_provider_url=r"http://c.tile.stamen.com/watercolor/{Z}/{X}/{Y}.jpg",
    tile_attribution='Map tiles by <a href="http://stamen.com">Stamen Design</a>, under <a href="http://creativecommons.org/licenses/by/3.0">CC BY 3.0</a>. Data by <a href="http://openstreetmap.org">OpenStreetMap</a>, under <a href="http://www.openstreetmap.org/copyright">ODbL</a>.'
    )

US_States_3

Using hovertool_string, one can pass a string that can contain arbitrary HTML elements (including divs, images, ...) that is shown when hovering over the geographies (@{column} will be replaced by the value of the column for the element the mouse hovers over, see also Bokeh documentation).

Here, we also used an OSM tile server with watercolor style via tile_provider_url and added the attribution via tile_attribution.

Sliders

Another option for interactive choropleth maps is the slider implementation of Pandas-Bokeh. The possible keyword arguments are here:

  • slider: By passing a list of column names of the GeoDataFrame, a slider can be used to . This dropdown menu can be used to select the choropleth layer by the user.
  • slider_range: Pass a range (or numpy.arange) of numbers object to relate the sliders values with the slider columns. By passing range(0,10), the slider will have values [0, 1, 2, ..., 9], when passing numpy.arange(3,5,0.5), the slider will have values [3, 3.5, 4, 4.5]. Default: range(0, len(slider))
  • slider_name: Specifies the title of the slider. Default is an empty string.

This can be used to display the change in population relative to the year 2010:


#Calculate change of population relative to 2010:
for i in range(8):
    df_states["Delta_Population_201%d"%i] = ((df_states["POPESTIMATE201%d"%i] / df_states["POPESTIMATE2010"]) -1 ) * 100

#Specify slider columns:
slider_columns = ["Delta_Population_201%d"%i for i in range(8)]

#Specify slider-range (Maps "Delta_Population_2010" -> 2010, 
#                           "Delta_Population_2011" -> 2011, ...):
slider_range = range(2010, 2018)

#Make slider plot:
df_states.plot_bokeh(
    figsize=(900, 600),
    simplify_shapes=5000,
    slider=slider_columns,
    slider_range=slider_range,
    slider_name="Year", 
    colormap="Inferno",
    hovertool_columns=["STATE_NAME"] + slider_columns,
    title="Change of Population [%]")

US_States_4



 

Plot multiple geolayers

If you wish to display multiple geolayers, you can pass the Bokeh figure of a Pandas-Bokeh plot via the figure keyword to the next plot_bokeh() call:

import geopandas as gpd
import pandas_bokeh
pandas_bokeh.output_notebook()

# Read in GeoJSONs from URL:
df_states = gpd.read_file(r"https://raw.githubusercontent.com/PatrikHlobil/Pandas-Bokeh/master/docs/Testdata/states/states.geojson")
df_cities = gpd.read_file(
    r"https://raw.githubusercontent.com/PatrikHlobil/Pandas-Bokeh/master/docs/Testdata/populated%20places/ne_10m_populated_places_simple_bigcities.geojson"
)
df_cities["size"] = df_cities.pop_max / 400000

#Plot shapes of US states (pass figure options to this initial plot):
figure = df_states.plot_bokeh(
    figsize=(800, 450),
    simplify_shapes=10000,
    show_figure=False,
    xlim=[-170, -80],
    ylim=[10, 70],
    category="REGION",
    colormap="Dark2",
    legend="States",
    show_colorbar=False,
)

#Plot cities as points on top of the US states layer by passing the figure:
df_cities.plot_bokeh(
    figure=figure,         # <== pass figure here!
    category="pop_max",
    colormap="Viridis",
    colormap_uselog=True,
    size="size",
    hovertool_string="""<h1>@name</h1>
                        <h3>Population: @pop_max </h3>""",
    marker="inverted_triangle",
    legend="Cities",
)

Multiple Geolayers


Point & Line plots:

Below, you can see an example that use Pandas-Bokeh to plot point data on a map. The plot shows all cities with a population larger than 1.000.000. For point plots, you can select the marker as keyword argument (since it is passed to bokeh.plotting.figure.scatter). Here an overview of all available marker types:

gdf = gpd.read_file(r"https://raw.githubusercontent.com/PatrikHlobil/Pandas-Bokeh/master/docs/Testdata/populated%20places/ne_10m_populated_places_simple_bigcities.geojson")
gdf["size"] = gdf.pop_max / 400000

gdf.plot_bokeh(
    category="pop_max",
    colormap="Viridis",
    colormap_uselog=True,
    size="size",
    hovertool_string="""<h1>@name</h1>
                        <h3>Population: @pop_max </h3>""",
    xlim=[-15, 35],
    ylim=[30,60],
    marker="inverted_triangle");

Pointmap

In a similar way, also GeoDataFrames with (multi)line shapes can be drawn using Pandas-Bokeh.


 


Colorbar formatting:

If you want to display the numerical labels on your colorbar with an alternative to the scientific format, you can pass in a one of the bokeh number string formats or an instance of one of the bokeh.models.formatters to the colorbar_tick_format argument in the geoplot

An example of using the string format argument:

df_states = gpd.read_file(r"https://raw.githubusercontent.com/PatrikHlobil/Pandas-Bokeh/master/docs/Testdata/states/states.geojson")

df_states["STATE_NAME_SMALL"] = df_states["STATE_NAME"].str.lower()

# pass in a string format to colorbar_tick_format to display the ticks as 10m rather than 1e7
df_states.plot_bokeh(
    figsize=(900, 600),
    category="POPESTIMATE2017",
    simplify_shapes=5000,    
    colormap="Inferno",
    colormap_uselog=True,
    colorbar_tick_format="0.0a")

colorbar_tick_format with string argument

An example of using the bokeh PrintfTickFormatter:

df_states = gpd.read_file(r"https://raw.githubusercontent.com/PatrikHlobil/Pandas-Bokeh/master/docs/Testdata/states/states.geojson")

df_states["STATE_NAME_SMALL"] = df_states["STATE_NAME"].str.lower()

for i in range(8):
    df_states["Delta_Population_201%d"%i] = ((df_states["POPESTIMATE201%d"%i] / df_states["POPESTIMATE2010"]) -1 ) * 100

# pass in a PrintfTickFormatter instance colorbar_tick_format to display the ticks with 2 decimal places  
df_states.plot_bokeh(
    figsize=(900, 600),
    category="Delta_Population_2017",
    simplify_shapes=5000,    
    colormap="Inferno",
    colorbar_tick_format=PrintfTickFormatter(format="%4.2f"))

colorbar_tick_format with bokeh.models.formatter_instance


Outputs, Formatting & Layouts

Output options

The pandas.DataFrame.plot_bokeh API has the following additional keyword arguments:

  • show_figure: If True, the resulting figure is shown (either in the notebook or exported and shown as HTML file, see Basics. If False, None is returned. Default: True
  • return_html: If True, the method call returns an HTML string that contains all Bokeh CSS&JS resources and the figure embedded in a div. This HTML representation of the plot can be used for embedding the plot in an HTML document. Default: False

If you have a Bokeh figure or layout, you can also use the pandas_bokeh.embedded_html function to generate an embeddable HTML representation of the plot. This can be included into any valid HTML (note that this is not possible directly with the HTML generated by the pandas_bokeh.output_file output option, because it includes an HTML header). Let us consider the following simple example:

#Import Pandas and Pandas-Bokeh (if you do not specify an output option, the standard is
#output_file):
import pandas as pd
import pandas_bokeh

#Create DataFrame to Plot:
import numpy as np
x = np.arange(-10, 10, 0.1)
sin = np.sin(x)
cos = np.cos(x)
tan = np.tan(x)
df = pd.DataFrame({"x": x, "sin(x)": sin, "cos(x)": cos, "tan(x)": tan})

#Make Bokeh plot from DataFrame using Pandas-Bokeh. Do not show the plot, but export
#it to an embeddable HTML string:
html_plot = df.plot_bokeh(
    kind="line",
    x="x",
    y=["sin(x)", "cos(x)", "tan(x)"],
    xticks=range(-20, 20),
    title="Trigonometric functions",
    show_figure=False,
    return_html=True,
    ylim=(-1.5, 1.5))

#Write some HTML and embed the HTML plot below it. For production use, please use
#Templates and the awesome Jinja library.
html = r"""
<script type="text/x-mathjax-config">
  MathJax.Hub.Config({tex2jax: {inlineMath: [['$','$'], ['\\(','\\)']]}});
</script>
<script type="text/javascript"
  src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML">
</script>

<h1> Trigonometric functions </h1>

<p> The basic trigonometric functions are:</p>

<p>$ sin(x) $</p>
<p>$ cos(x) $</p>
<p>$ tan(x) = \frac{sin(x)}{cos(x)}$</p>

<p>Below is a plot that shows them</p>

""" + html_plot

#Export the HTML string to an external HTML file and show it:
with open("test.html" , "w") as f:
    f.write(html)
    
import webbrowser
webbrowser.open("test.html")

This code will open up a webbrowser and show the following page. As you can see, the interactive Bokeh plot is embedded nicely into the HTML layout. The return_html option is ideal for the use in a templating engine like Jinja.

Embedded HTML

Auto Scaling Plots

For single plots that have a number of x axis values or for larger monitors, you can auto scale the figure to the width of the entire jupyter cell by setting the sizing_mode parameter.

df = pd.DataFrame(np.random.rand(10, 4), columns=['a', 'b', 'c', 'd']) df.plot_bokeh(kind="bar", figsize=(500, 200), sizing_mode="scale_width")

Scaled Plot

The figsize parameter can be used to change the height and width as well as act as a scaling multiplier against the axis that is not being scaled.

 

Number formats

To change the formats of numbers in the hovertool, use the number_format keyword argument. For a documentation about the format to pass, have a look at the Bokeh documentation.Let us consider some examples for the number 3.141592653589793:

FormatOutput
03
0.0003.141
0.00 $3.14 $

This number format will be applied to all numeric columns of the hovertool. If you want to make a very custom or complicated hovertool, you should probably use the hovertool_string keyword argument, see e.g. this example. Below, we use the number_format parameter to specify the "Stock Price" format to 2 decimal digits and an additional $ sign.

import numpy as np

#Lineplot:
np.random.seed(42)
df = pd.DataFrame({
    "Google": np.random.randn(1000) + 0.2,
    "Apple": np.random.randn(1000) + 0.17
},
                  index=pd.date_range('1/1/2000', periods=1000))
df = df.cumsum()
df = df + 50
df.plot_bokeh(
    kind="line",
    title="Apple vs Google",
    xlabel="Date",
    ylabel="Stock price [$]",
    yticks=[0, 100, 200, 300, 400],
    ylim=(0, 400),
    colormap=["red", "blue"],
    number_format="1.00 $")

Number format

Suppress scientific notation for axes

If you want to suppress the scientific notation for axes, you can use the disable_scientific_axes parameter, which accepts one of "x", "y", "xy":

df = pd.DataFrame({"Animal": ["Mouse", "Rabbit", "Dog", "Tiger", "Elefant", "Wale"],
                   "Weight [g]": [19, 3000, 40000, 200000, 6000000, 50000000]})
p_scientific = df.plot_bokeh(x="Animal", y="Weight [g]", show_figure=False)
p_non_scientific = df.plot_bokeh(x="Animal", y="Weight [g]", disable_scientific_axes="y", show_figure=False,)
pandas_bokeh.plot_grid([[p_scientific, p_non_scientific]], plot_width = 450)

Number format

 

Dashboard Layouts

As shown in the Scatterplot Example, combining plots with plots or other HTML elements is straighforward in Pandas-Bokeh due to the layout capabilities of Bokeh. The easiest way to generate a dashboard layout is using the pandas_bokeh.plot_grid method (which is an extension of bokeh.layouts.gridplot):

import pandas as pd
import numpy as np
import pandas_bokeh
pandas_bokeh.output_notebook()

#Barplot:
data = {
    'fruits':
    ['Apples', 'Pears', 'Nectarines', 'Plums', 'Grapes', 'Strawberries'],
    '2015': [2, 1, 4, 3, 2, 4],
    '2016': [5, 3, 3, 2, 4, 6],
    '2017': [3, 2, 4, 4, 5, 3]
}
df = pd.DataFrame(data).set_index("fruits")
p_bar = df.plot_bokeh(
    kind="bar",
    ylabel="Price per Unit [€]",
    title="Fruit prices per Year",
    show_figure=False)

#Lineplot:
np.random.seed(42)
df = pd.DataFrame({
    "Google": np.random.randn(1000) + 0.2,
    "Apple": np.random.randn(1000) + 0.17
},
                  index=pd.date_range('1/1/2000', periods=1000))
df = df.cumsum()
df = df + 50
p_line = df.plot_bokeh(
    kind="line",
    title="Apple vs Google",
    xlabel="Date",
    ylabel="Stock price [$]",
    yticks=[0, 100, 200, 300, 400],
    ylim=(0, 400),
    colormap=["red", "blue"],
    show_figure=False)

#Scatterplot:
from sklearn.datasets import load_iris
iris = load_iris()
df = pd.DataFrame(iris["data"])
df.columns = iris["feature_names"]
df["species"] = iris["target"]
df["species"] = df["species"].map(dict(zip(range(3), iris["target_names"])))
p_scatter = df.plot_bokeh(
    kind="scatter",
    x="petal length (cm)",
    y="sepal width (cm)",
    category="species",
    title="Iris DataSet Visualization",
    show_figure=False)

#Histogram:
df_hist = pd.DataFrame({
    'a': np.random.randn(1000) + 1,
    'b': np.random.randn(1000),
    'c': np.random.randn(1000) - 1
},
                       columns=['a', 'b', 'c'])

p_hist = df_hist.plot_bokeh(
    kind="hist",
    bins=np.arange(-6, 6.5, 0.5),
    vertical_xlabel=True,
    normed=100,
    hovertool=False,
    title="Normal distributions",
    show_figure=False)

#Make Dashboard with Grid Layout:
pandas_bokeh.plot_grid([[p_line, p_bar], 
                        [p_scatter, p_hist]], plot_width=450)

Dashboard Layout

Using a combination of row and column elements (see also Bokeh Layouts) allow for a very easy general arrangement of elements. An alternative layout to the one above is:

p_line.plot_width = 900
p_hist.plot_width = 900

layout = pandas_bokeh.column(p_line,
                pandas_bokeh.row(p_scatter, p_bar),
                p_hist)

pandas_bokeh.show(layout)

Alternative Dashboard Layout


 



 

 

Release Notes

Release Notes can be found here.

Contributing to Pandas-Bokeh

If you wish to contribute to the development of Pandas-Bokeh you can follow the instructions on the CONTRIBUTING.md.

 

Author: PatrikHlobil
Source Code: https://github.com/PatrikHlobil/Pandas-Bokeh 
License: MIT License

#machine-learning  #datavisualizations #python 

Dylan  Iqbal

Dylan Iqbal

1561523460

Matplotlib Cheat Sheet: Plotting in Python

This Matplotlib cheat sheet introduces you to the basics that you need to plot your data with Python and includes code samples.

Data visualization and storytelling with your data are essential skills that every data scientist needs to communicate insights gained from analyses effectively to any audience out there. 

For most beginners, the first package that they use to get in touch with data visualization and storytelling is, naturally, Matplotlib: it is a Python 2D plotting library that enables users to make publication-quality figures. But, what might be even more convincing is the fact that other packages, such as Pandas, intend to build more plotting integration with Matplotlib as time goes on.

However, what might slow down beginners is the fact that this package is pretty extensive. There is so much that you can do with it and it might be hard to still keep a structure when you're learning how to work with Matplotlib.   

DataCamp has created a Matplotlib cheat sheet for those who might already know how to use the package to their advantage to make beautiful plots in Python, but that still want to keep a one-page reference handy. Of course, for those who don't know how to work with Matplotlib, this might be the extra push be convinced and to finally get started with data visualization in Python. 

You'll see that this cheat sheet presents you with the six basic steps that you can go through to make beautiful plots. 

Check out the infographic by clicking on the button below:

Python Matplotlib cheat sheet

With this handy reference, you'll familiarize yourself in no time with the basics of Matplotlib: you'll learn how you can prepare your data, create a new plot, use some basic plotting routines to your advantage, add customizations to your plots, and save, show and close the plots that you make.

What might have looked difficult before will definitely be more clear once you start using this cheat sheet! Use it in combination with the Matplotlib Gallery, the documentation.

Matplotlib 

Matplotlib is a Python 2D plotting library which produces publication-quality figures in a variety of hardcopy formats and interactive environments across platforms.

Prepare the Data 

1D Data 

>>> import numpy as np
>>> x = np.linspace(0, 10, 100)
>>> y = np.cos(x)
>>> z = np.sin(x)

2D Data or Images 

>>> data = 2 * np.random.random((10, 10))
>>> data2 = 3 * np.random.random((10, 10))
>>> Y, X = np.mgrid[-3:3:100j, -3:3:100j]
>>> U = 1 X** 2 + Y
>>> V = 1 + X Y**2
>>> from matplotlib.cbook import get_sample_data
>>> img = np.load(get_sample_data('axes_grid/bivariate_normal.npy'))

Create Plot

>>> import matplotlib.pyplot as plt

Figure 

>>> fig = plt.figure()
>>> fig2 = plt.figure(figsize=plt.figaspect(2.0))

Axes 

>>> fig.add_axes()
>>> ax1 = fig.add_subplot(221) #row-col-num
>>> ax3 = fig.add_subplot(212)
>>> fig3, axes = plt.subplots(nrows=2,ncols=2)
>>> fig4, axes2 = plt.subplots(ncols=3)

Save Plot 

>>> plt.savefig('foo.png') #Save figures
>>> plt.savefig('foo.png',  transparent=True) #Save transparent figures

Show Plot

>>> plt.show()

Plotting Routines 

1D Data 

>>> fig, ax = plt.subplots()
>>> lines = ax.plot(x,y) #Draw points with lines or markers connecting them
>>> ax.scatter(x,y) #Draw unconnected points, scaled or colored
>>> axes[0,0].bar([1,2,3],[3,4,5]) #Plot vertical rectangles (constant width)
>>> axes[1,0].barh([0.5,1,2.5],[0,1,2]) #Plot horiontal rectangles (constant height)
>>> axes[1,1].axhline(0.45) #Draw a horizontal line across axes
>>> axes[0,1].axvline(0.65) #Draw a vertical line across axes
>>> ax.fill(x,y,color='blue') #Draw filled polygons
>>> ax.fill_between(x,y,color='yellow') #Fill between y values and 0

2D Data 

>>> fig, ax = plt.subplots()
>>> im = ax.imshow(img, #Colormapped or RGB arrays
      cmap= 'gist_earth', 
      interpolation= 'nearest',
      vmin=-2,
      vmax=2)
>>> axes2[0].pcolor(data2) #Pseudocolor plot of 2D array
>>> axes2[0].pcolormesh(data) #Pseudocolor plot of 2D array
>>> CS = plt.contour(Y,X,U) #Plot contours
>>> axes2[2].contourf(data1) #Plot filled contours
>>> axes2[2]= ax.clabel(CS) #Label a contour plot

Vector Fields 

>>> axes[0,1].arrow(0,0,0.5,0.5) #Add an arrow to the axes
>>> axes[1,1].quiver(y,z) #Plot a 2D field of arrows
>>> axes[0,1].streamplot(X,Y,U,V) #Plot a 2D field of arrows

Data Distributions 

>>> ax1.hist(y) #Plot a histogram
>>> ax3.boxplot(y) #Make a box and whisker plot
>>> ax3.violinplot(z)  #Make a violin plot

Plot Anatomy & Workflow 

Plot Anatomy 

 y-axis      

                           x-axis 

Workflow 

The basic steps to creating plots with matplotlib are:

1 Prepare Data
2 Create Plot
3 Plot
4 Customized Plot
5 Save Plot
6 Show Plot

>>> import matplotlib.pyplot as plt
>>> x = [1,2,3,4]  #Step 1
>>> y = [10,20,25,30] 
>>> fig = plt.figure() #Step 2
>>> ax = fig.add_subplot(111) #Step 3
>>> ax.plot(x, y, color= 'lightblue', linewidth=3)  #Step 3, 4
>>> ax.scatter([2,4,6],
          [5,15,25],
          color= 'darkgreen',
          marker= '^' )
>>> ax.set_xlim(1, 6.5)
>>> plt.savefig('foo.png' ) #Step 5
>>> plt.show() #Step 6

Close and Clear 

>>> plt.cla()  #Clear an axis
>>> plt.clf(). #Clear the entire figure
>>> plt.close(). #Close a window

Plotting Customize Plot 

Colors, Color Bars & Color Maps 

>>> plt.plot(x, x, x, x**2, x, x** 3)
>>> ax.plot(x, y, alpha = 0.4)
>>> ax.plot(x, y, c= 'k')
>>> fig.colorbar(im, orientation= 'horizontal')
>>> im = ax.imshow(img,
            cmap= 'seismic' )

Markers 

>>> fig, ax = plt.subplots()
>>> ax.scatter(x,y,marker= ".")
>>> ax.plot(x,y,marker= "o")

Linestyles 

>>> plt.plot(x,y,linewidth=4.0)
>>> plt.plot(x,y,ls= 'solid') 
>>> plt.plot(x,y,ls= '--') 
>>> plt.plot(x,y,'--' ,x**2,y**2,'-.' ) 
>>> plt.setp(lines,color= 'r',linewidth=4.0)

Text & Annotations 

>>> ax.text(1,
           -2.1, 
           'Example Graph', 
            style= 'italic' )
>>> ax.annotate("Sine", 
xy=(8, 0),
xycoords= 'data', 
xytext=(10.5, 0),
textcoords= 'data', 
arrowprops=dict(arrowstyle= "->", 
connectionstyle="arc3"),)

Mathtext 

>>> plt.title(r '$sigma_i=15$', fontsize=20)

Limits, Legends and Layouts 

Limits & Autoscaling 

>>> ax.margins(x=0.0,y=0.1) #Add padding to a plot
>>> ax.axis('equal')  #Set the aspect ratio of the plot to 1
>>> ax.set(xlim=[0,10.5],ylim=[-1.5,1.5])  #Set limits for x-and y-axis
>>> ax.set_xlim(0,10.5) #Set limits for x-axis

Legends 

>>> ax.set(title= 'An Example Axes',  #Set a title and x-and y-axis labels
            ylabel= 'Y-Axis', 
            xlabel= 'X-Axis')
>>> ax.legend(loc= 'best')  #No overlapping plot elements

Ticks 

>>> ax.xaxis.set(ticks=range(1,5),  #Manually set x-ticks
             ticklabels=[3,100, 12,"foo" ])
>>> ax.tick_params(axis= 'y', #Make y-ticks longer and go in and out
             direction= 'inout', 
              length=10)

Subplot Spacing 

>>> fig3.subplots_adjust(wspace=0.5,   #Adjust the spacing between subplots
             hspace=0.3,
             left=0.125,
             right=0.9,
             top=0.9,
             bottom=0.1)
>>> fig.tight_layout() #Fit subplot(s) in to the figure area

Axis Spines 

>>> ax1.spines[ 'top'].set_visible(False) #Make the top axis line for a plot invisible
>>> ax1.spines['bottom' ].set_position(( 'outward',10))  #Move the bottom axis line outward

Have this Cheat Sheet at your fingertips

Original article source at https://www.datacamp.com

#matplotlib #cheatsheet #python

Jamison  Fisher

Jamison Fisher

1642995900

Pandas Bokeh: Bokeh Plotting Backend for Pandas and GeoPandas

Pandas-Bokeh provides a Bokeh plotting backend for Pandas, GeoPandas and Pyspark DataFrames, similar to the already existing Visualization feature of Pandas. Importing the library adds a complementary plotting method plot_bokeh() on DataFrames and Series.

With Pandas-Bokeh, creating stunning, interactive, HTML-based visualization is as easy as calling:

df.plot_bokeh()

Pandas-Bokeh also provides native support as a Pandas Plotting backend for Pandas >= 0.25. When Pandas-Bokeh is installed, switchting the default Pandas plotting backend to Bokeh can be done via:

pd.set_option('plotting.backend', 'pandas_bokeh')

More details about the new Pandas backend can be found below.

Interactive Documentation

Please visit:

https://patrikhlobil.github.io/Pandas-Bokeh/

for an interactive version of the documentation below, where you can play with the dynamic Bokeh plots.

For more information have a look at the Examples below or at notebooks on the Github Repository of this project.

Startimage

Installation

You can install Pandas-Bokeh from PyPI via pip

pip install pandas-bokeh

or conda:

conda install -c patrikhlobil pandas-bokeh

With the current release 0.5.5, Pandas-Bokeh officially supports Python 3.6 and newer. For more details, see Release Notes.

How To Use

Classical Use

 

The Pandas-Bokeh library should be imported after Pandas, GeoPandas and/or Pyspark. After the import, one should define the plotting output, which can be:

  • pandas_bokeh.output_notebook(): Embeds the Plots in the cell outputs of the notebook. Ideal when working in Jupyter Notebooks.
  • pandas_bokeh.output_file(filename): Exports the plot to the provided filename as an HTML.

For more details about the plotting outputs, see the reference here or the Bokeh documentation.

Notebook output (see also bokeh.io.output_notebook)

import pandas as pd
import pandas_bokeh
pandas_bokeh.output_notebook()

File output to "Interactive Plot.html" (see also bokeh.io.output_file)

import pandas as pd
import pandas_bokeh
pandas_bokeh.output_file("Interactive Plot.html")

Pandas-Bokeh as native Pandas plotting backend

For pandas >= 0.25, a plotting backend switch is natively supported. It can be achievied by calling:

import pandas as pd
pd.set_option('plotting.backend', 'pandas_bokeh')

Now, the plotting API is accessible for a Pandas DataFrame via:

df.plot(...)

All additional functionalities of Pandas-Bokeh are then accessible at pd.plotting. So, setting the output to notebook is:

pd.plotting.output_notebook()

or calling the grid layout functionality:

pd.plotting.plot_grid(...)

Note: Backwards compatibility is kept since there will still be the df.plot_bokeh(...) methods for a DataFrame.

Plot types

Supported plottypes are at the moment:

Also, check out the complementary chapter Outputs, Formatting & Layouts about:

Lineplot

Basic Lineplot

This simple lineplot in Pandas-Bokeh already contains various interactive elements:

  • a pannable and zoomable (zoom in plotarea and zoom on axis) plot
  • by clicking on the legend elements, one can hide and show the individual lines
  • a Hovertool for the plotted lines

Consider the following simple example:

import numpy as np

np.random.seed(42)
df = pd.DataFrame({"Google": np.random.randn(1000)+0.2, 
                   "Apple": np.random.randn(1000)+0.17}, 
                   index=pd.date_range('1/1/2000', periods=1000))
df = df.cumsum()
df = df + 50
df.plot_bokeh(kind="line")       #equivalent to df.plot_bokeh.line()

ApplevsGoogle_1

Note, that similar to the regular pandas.DataFrame.plot method, there are also additional accessors to directly access the different plotting types like:

  • df.plot_bokeh(kind="line", ...)df.plot_bokeh.line(...)
  • df.plot_bokeh(kind="bar", ...)df.plot_bokeh.bar(...)
  • df.plot_bokeh(kind="hist", ...)df.plot_bokeh.hist(...)
  • ...

Advanced Lineplot

There are various optional parameters to tune the plots, for example:

  • kind: Which kind of plot should be produced. Currently supported are: "line", "point", "scatter", "bar" and "histogram". In the near future many more will be implemented as horizontal barplot, boxplots, pie-charts, etc.
  • x: Name of the column to use for the horizontal x-axis. If the x parameter is not specified, the index is used for the x-values of the plot. Alternative, also an array of values can be passed that has the same number of elements as the DataFrame.
  • y: Name of column or list of names of columns to use for the vertical y-axis.
  • figsize: Choose width & height of the plot
  • title: Sets title of the plot
  • xlim/ylim: Set visibler range of plot for x- and y-axis (also works for datetime x-axis)
  • xlabel/ylabel: Set x- and y-labels
  • logx/logy: Set log-scale on x-/y-axis
  • xticks/yticks: Explicitly set the ticks on the axes
  • color: Defines a single color for a plot.
  • colormap: Can be used to specify multiple colors to plot. Can be either a list of colors or the name of a Bokeh color palette
  • hovertool: If True a Hovertool is active, else if False no Hovertool is drawn.
  • hovertool_string: If specified, this string will be used for the hovertool (@{column} will be replaced by the value of the column for the element the mouse hovers over, see also Bokeh documentation and here)
  • toolbar_location: Specify the position of the toolbar location (None, "above", "below", "left" or "right"). Default: "right"
  • zooming: Enables/Disables zooming. Default: True
  • panning: Enables/Disables panning. Default: True
  • fontsize_label/fontsize_ticks/fontsize_title/fontsize_legend: Set fontsize of labels, ticks, title or legend (int or string of form "15pt")
  • rangetool Enables a range tool scroller. Default False
  • kwargs**: Optional keyword arguments of bokeh.plotting.figure.line

Try them out to get a feeling for the effects. Let us consider now:

df.plot_bokeh.line(
    figsize=(800, 450),
    y="Apple",
    title="Apple vs Google",
    xlabel="Date",
    ylabel="Stock price [$]",
    yticks=[0, 100, 200, 300, 400],
    ylim=(0, 400),
    toolbar_location=None,
    colormap=["red", "blue"],
    hovertool_string=r"""<img
                        src='https://upload.wikimedia.org/wikipedia/commons/thumb/f/fa/Apple_logo_black.svg/170px-Apple_logo_black.svg.png' 
                        height="42" alt="@imgs" width="42"
                        style="float: left; margin: 0px 15px 15px 0px;"
                        border="2"></img> Apple 
                        
                        <h4> Stock Price: </h4> @{Apple}""",
    panning=False,
    zooming=False)

ApplevsGoogle_2

Lineplot with data points

For lineplots, as for many other plot-kinds, there are some special keyword arguments that only work for this plotting type. For lineplots, these are:

  • plot_data_points: Plot also the data points on the lines
  • plot_data_points_size: Determines the size of the data points
  • marker: Defines the point type (Default: "circle"). Possible values are: 'circle', 'square', 'triangle', 'asterisk', 'circle_x', 'square_x', 'inverted_triangle', 'x', 'circle_cross', 'square_cross', 'diamond', 'cross'
  • kwargs**: Optional keyword arguments of bokeh.plotting.figure.line

Let us use this information to have another version of the same plot:

df.plot_bokeh.line(
    figsize=(800, 450),
    title="Apple vs Google",
    xlabel="Date",
    ylabel="Stock price [$]",
    yticks=[0, 100, 200, 300, 400],
    ylim=(100, 200),
    xlim=("2001-01-01", "2001-02-01"),
    colormap=["red", "blue"],
    plot_data_points=True,
    plot_data_points_size=10,
    marker="asterisk")

ApplevsGoogle_3

Lineplot with rangetool

ts = pd.Series(np.random.randn(1000), index=pd.date_range('1/1/2000', periods=1000))
df = pd.DataFrame(np.random.randn(1000, 4), index=ts.index, columns=list('ABCD'))
df = df.cumsum()

df.plot_bokeh(rangetool=True)

rangetool

Pointplot

If you just wish to draw the date points for curves, the pointplot option is the right choice. It also accepts the kwargs of bokeh.plotting.figure.scatter like marker or size:

import numpy as np

x = np.arange(-3, 3, 0.1)
y2 = x**2
y3 = x**3
df = pd.DataFrame({"x": x, "Parabula": y2, "Cube": y3})
df.plot_bokeh.point(
    x="x",
    xticks=range(-3, 4),
    size=5,
    colormap=["#009933", "#ff3399"],
    title="Pointplot (Parabula vs. Cube)",
    marker="x")

Pointplot

Stepplot

With a similar API as the line- & pointplots, one can generate a stepplot. Additional keyword arguments for this plot type are passes to bokeh.plotting.figure.step, e.g. mode (before, after, center), see the following example

import numpy as np

x = np.arange(-3, 3, 1)
y2 = x**2
y3 = x**3
df = pd.DataFrame({"x": x, "Parabula": y2, "Cube": y3})
df.plot_bokeh.step(
    x="x",
    xticks=range(-1, 1),
    colormap=["#009933", "#ff3399"],
    title="Pointplot (Parabula vs. Cube)",
    figsize=(800,300),
    fontsize_title=30,
    fontsize_label=25,
    fontsize_ticks=15,
    fontsize_legend=5,
    )

df.plot_bokeh.step(
    x="x",
    xticks=range(-1, 1),
    colormap=["#009933", "#ff3399"],
    title="Pointplot (Parabula vs. Cube)",
    mode="after",
    figsize=(800,300)
    )

Stepplot

Note that the step-plot API of Bokeh does so far not support a hovertool functionality.

Scatterplot

A basic scatterplot can be created using the kind="scatter" option. For scatterplots, the x and y parameters have to be specified and the following optional keyword argument is allowed:

category: Determines the category column to use for coloring the scatter points

kwargs**: Optional keyword arguments of bokeh.plotting.figure.scatter

Note, that the pandas.DataFrame.plot_bokeh() method return per default a Bokeh figure, which can be embedded in Dashboard layouts with other figures and Bokeh objects (for more details about (sub)plot layouts and embedding the resulting Bokeh plots as HTML click here).

In the example below, we use the building grid layout support of Pandas-Bokeh to display both the DataFrame (using a Bokeh DataTable) and the resulting scatterplot:

# Load Iris Dataset:
df = pd.read_csv(
    r"https://raw.githubusercontent.com/PatrikHlobil/Pandas-Bokeh/master/docs/Testdata/iris/iris.csv"
)
df = df.sample(frac=1)

# Create Bokeh-Table with DataFrame:
from bokeh.models.widgets import DataTable, TableColumn
from bokeh.models import ColumnDataSource

data_table = DataTable(
    columns=[TableColumn(field=Ci, title=Ci) for Ci in df.columns],
    source=ColumnDataSource(df),
    height=300,
)

# Create Scatterplot:
p_scatter = df.plot_bokeh.scatter(
    x="petal length (cm)",
    y="sepal width (cm)",
    category="species",
    title="Iris DataSet Visualization",
    show_figure=False,
)

# Combine Table and Scatterplot via grid layout:
pandas_bokeh.plot_grid([[data_table, p_scatter]], plot_width=400, plot_height=350)

 

Scatterplot

A possible optional keyword parameters that can be passed to bokeh.plotting.figure.scatter is size. Below, we use the sepal length of the Iris data as reference for the size:

#Change one value to clearly see the effect of the size keyword
df.loc[13, "sepal length (cm)"] = 15

#Make scatterplot:
p_scatter = df.plot_bokeh.scatter(
    x="petal length (cm)",
    y="sepal width (cm)",
    category="species",
    title="Iris DataSet Visualization with Size Keyword",
    size="sepal length (cm)")

Scatterplot2

In this example you can see, that the additional dimension sepal length cannot be used to clearly differentiate between the virginica and versicolor species.

Barplot

The barplot API has no special keyword arguments, but accepts optional kwargs of bokeh.plotting.figure.vbar like alpha. It uses per default the index for the bar categories (however, also columns can be used as x-axis category using the x argument).

data = {
    'fruits':
    ['Apples', 'Pears', 'Nectarines', 'Plums', 'Grapes', 'Strawberries'],
    '2015': [2, 1, 4, 3, 2, 4],
    '2016': [5, 3, 3, 2, 4, 6],
    '2017': [3, 2, 4, 4, 5, 3]
}
df = pd.DataFrame(data).set_index("fruits")

p_bar = df.plot_bokeh.bar(
    ylabel="Price per Unit [€]", 
    title="Fruit prices per Year", 
    alpha=0.6)

Barplot

Using the stacked keyword argument you also maked stacked barplots:

p_stacked_bar = df.plot_bokeh.bar(
    ylabel="Price per Unit [€]",
    title="Fruit prices per Year",
    stacked=True,
    alpha=0.6)

Barplot2

Also horizontal versions of the above barplot are supported with the keyword kind="barh" or the accessor plot_bokeh.barh. You can still specify a column of the DataFrame as the bar category via the x argument if you do not wish to use the index.

#Reset index, such that "fruits" is now a column of the DataFrame:
df.reset_index(inplace=True)

#Create horizontal bar (via kind keyword):
p_hbar = df.plot_bokeh(
    kind="barh",
    x="fruits",
    xlabel="Price per Unit [€]",
    title="Fruit prices per Year",
    alpha=0.6,
    legend = "bottom_right",
    show_figure=False)

#Create stacked horizontal bar (via barh accessor):
p_stacked_hbar = df.plot_bokeh.barh(
    x="fruits",
    stacked=True,
    xlabel="Price per Unit [€]",
    title="Fruit prices per Year",
    alpha=0.6,
    legend = "bottom_right",
    show_figure=False)

#Plot all barplot examples in a grid:
pandas_bokeh.plot_grid([[p_bar, p_stacked_bar],
                        [p_hbar, p_stacked_hbar]], 
                       plot_width=450)

Barplot3

Histogram

For drawing histograms (kind="hist"), Pandas-Bokeh has a lot of customization features. Optional keyword arguments for histogram plots are:

  • bins: Determines bins to use for the histogram. If bins is an int, it defines the number of equal-width bins in the given range (10, by default). If bins is a sequence, it defines the bin edges, including the rightmost edge, allowing for non-uniform bin widths. If bins is a string, it defines the method used to calculate the optimal bin width, as defined by histogram_bin_edges.
  • histogram_type: Either "sidebyside", "topontop" or "stacked". Default: "topontop"
  • stacked: Boolean that overrides the histogram_type as "stacked" if given. Default: False
  • kwargs**: Optional keyword arguments of bokeh.plotting.figure.quad

Below examples of the different histogram types:

import numpy as np

df_hist = pd.DataFrame({
    'a': np.random.randn(1000) + 1,
    'b': np.random.randn(1000),
    'c': np.random.randn(1000) - 1
    },
    columns=['a', 'b', 'c'])

#Top-on-Top Histogram (Default):
df_hist.plot_bokeh.hist(
    bins=np.linspace(-5, 5, 41),
    vertical_xlabel=True,
    hovertool=False,
    title="Normal distributions (Top-on-Top)",
    line_color="black")

#Side-by-Side Histogram (multiple bars share bin side-by-side) also accessible via
#kind="hist":
df_hist.plot_bokeh(
    kind="hist",
    bins=np.linspace(-5, 5, 41),
    histogram_type="sidebyside",
    vertical_xlabel=True,
    hovertool=False,
    title="Normal distributions (Side-by-Side)",
    line_color="black")

#Stacked histogram:
df_hist.plot_bokeh.hist(
    bins=np.linspace(-5, 5, 41),
    histogram_type="stacked",
    vertical_xlabel=True,
    hovertool=False,
    title="Normal distributions (Stacked)",
    line_color="black")

Histogram

Further, advanced keyword arguments for histograms are:

  • weights: A column of the DataFrame that is used as weight for the histogramm aggregation (see also numpy.histogram)
  • normed: If True, histogram values are normed to 1 (sum of histogram values=1). It is also possible to pass an integer, e.g. normed=100 would result in a histogram with percentage y-axis (sum of histogram values=100). Default: False
  • cumulative: If True, a cumulative histogram is shown. Default: False
  • show_average: If True, the average of the histogram is also shown. Default: False

Their usage is shown in these examples:

p_hist = df_hist.plot_bokeh.hist(
    y=["a", "b"],
    bins=np.arange(-4, 6.5, 0.5),
    normed=100,
    vertical_xlabel=True,
    ylabel="Share[%]",
    title="Normal distributions (normed)",
    show_average=True,
    xlim=(-4, 6),
    ylim=(0, 30),
    show_figure=False)

p_hist_cum = df_hist.plot_bokeh.hist(
    y=["a", "b"],
    bins=np.arange(-4, 6.5, 0.5),
    normed=100,
    cumulative=True,
    vertical_xlabel=True,
    ylabel="Share[%]",
    title="Normal distributions (normed & cumulative)",
    show_figure=False)

pandas_bokeh.plot_grid([[p_hist, p_hist_cum]], plot_width=450, plot_height=300)

Histogram2

Areaplot

Areaplot (kind="area") can be either drawn on top of each other or stacked. The important parameters are:

stacked: If True, the areaplots are stacked. If False, plots are drawn on top of each other. Default: False

kwargs**: Optional keyword arguments of bokeh.plotting.figure.patch

Let us consider the energy consumption split by source that can be downloaded as DataFrame via:

df_energy = pd.read_csv(r"https://raw.githubusercontent.com/PatrikHlobil/Pandas-Bokeh/master/docs/Testdata/energy/energy.csv", 
parse_dates=["Year"])
df_energy.head()
YearOilGasCoalNuclear EnergyHydroelectricityOther Renewable
1970-01-012291.5826.71467.317.7265.85.8
1971-01-012427.7884.81459.224.9276.46.3
1972-01-012613.9933.71475.734.1288.96.8
1973-01-012818.1978.01519.645.9292.57.3
1974-01-012777.31001.91520.959.6321.17.7

Creating the Areaplot can be achieved via:

df_energy.plot_bokeh.area(
    x="Year",
    stacked=True,
    legend="top_left",
    colormap=["brown", "orange", "black", "grey", "blue", "green"],
    title="Worldwide energy consumption split by energy source",
    ylabel="Million tonnes oil equivalent",
    ylim=(0, 16000))

areaplot

Note that the energy consumption of fossile energy is still increasing and renewable energy sources are still small in comparison 😢!!! However, when we norm the plot using the normed keyword, there is a clear trend towards renewable energies in the last decade:

df_energy.plot_bokeh.area(
    x="Year",
    stacked=True,
    normed=100,
    legend="bottom_left",
    colormap=["brown", "orange", "black", "grey", "blue", "green"],
    title="Worldwide energy consumption split by energy source",
    ylabel="Million tonnes oil equivalent")

areaplot2

Pieplot

For Pieplots, let us consider a dataset showing the results of all Bundestags elections in Germany since 2002:

df_pie = pd.read_csv(r"https://raw.githubusercontent.com/PatrikHlobil/Pandas-Bokeh/master/docs/Testdata/Bundestagswahl/Bundestagswahl.csv")
df_pie
Partei20022005200920132017
CDU/CSU38.535.233.841.532.9
SPD38.534.223.025.720.5
FDP7.49.814.64.810.7
Grünen8.68.110.78.48.9
Linke/PDS4.08.711.98.69.2
AfD0.00.00.00.012.6
Sonstige3.04.06.011.05.0

We can create a Pieplot of the last election in 2017 by specifying the "Partei" (german for party) column as the x column and the "2017" column as the y column for values:

df_pie.plot_bokeh.pie(
    x="Partei",
    y="2017",
    colormap=["blue", "red", "yellow", "green", "purple", "orange", "grey"],
    title="Results of German Bundestag Election 2017",
    )

pieplot

When you pass several columns to the y parameter (not providing the y-parameter assumes you plot all columns), multiple nested pieplots will be shown in one plot:

df_pie.plot_bokeh.pie(
    x="Partei",
    colormap=["blue", "red", "yellow", "green", "purple", "orange", "grey"],
    title="Results of German Bundestag Elections [2002-2017]",
    line_color="grey")

pieplot2

Mapplot

The mapplot method of Pandas-Bokeh allows for plotting geographic points stored in a Pandas DataFrame on an interactive map. For more advanced Geoplots for line and polygon shapes have a look at the Geoplots examples for the GeoPandas API of Pandas-Bokeh.

For mapplots, only (latitude, longitude) pairs in geographic projection (WGS84) can be plotted on a map. The basic API has the following 2 base parameters:

  • x: name of the longitude column of the DataFrame
  • y: name of the latitude column of the DataFrame

The other optional keyword arguments are discussed in the section about the GeoPandas API, e.g. category for coloring the points.

Below an example of plotting all cities for more than 1 million inhabitants:

df_mapplot = pd.read_csv(r"https://raw.githubusercontent.com/PatrikHlobil/Pandas-Bokeh/master/docs/Testdata/populated%20places/populated_places.csv")
df_mapplot.head()
namepop_maxlatitudelongitudesize
Mesa108539433.423915-111.7360841.085394
Sharjah110302725.37138355.4064781.103027
Changwon108149935.219102128.5835621.081499
Sheffield129290053.366677-1.4999971.292900
Abbottabad118364734.14950373.1995011.183647
df_mapplot["size"] = df_mapplot["pop_max"] / 1000000
df_mapplot.plot_bokeh.map(
    x="longitude",
    y="latitude",
    hovertool_string="""<h2> @{name} </h2> 
    
                        <h3> Population: @{pop_max} </h3>""",
    tile_provider="STAMEN_TERRAIN_RETINA",
    size="size", 
    figsize=(900, 600),
    title="World cities with more than 1.000.000 inhabitants")

 

Mapplot

Geoplots

Pandas-Bokeh also allows for interactive plotting of Maps using GeoPandas by providing a geopandas.GeoDataFrame.plot_bokeh() method. It allows to plot the following geodata on a map :

  • Points/MultiPoints
  • Lines/MultiLines
  • Polygons/MultiPolygons

Note: t is not possible to mix up the objects types, i.e. a GeoDataFrame with Points and Lines is for example not allowed.

Les us start with a simple example using the "World Borders Dataset" . Let us first import all neccessary libraries and read the shapefile:

import geopandas as gpd
import pandas as pd
import pandas_bokeh
pandas_bokeh.output_notebook()

#Read in GeoJSON from URL:
df_states = gpd.read_file(r"https://raw.githubusercontent.com/PatrikHlobil/Pandas-Bokeh/master/docs/Testdata/states/states.geojson")
df_states.head()
STATE_NAMEREGIONPOPESTIMATE2010POPESTIMATE2011POPESTIMATE2012POPESTIMATE2013POPESTIMATE2014POPESTIMATE2015POPESTIMATE2016POPESTIMATE2017geometry
Hawaii413638171378323139277214080381417710142632014286831427538(POLYGON ((-160.0738033454681 22.0041773479577...
Washington467413866819155689089969634107046931715281872809347405743(POLYGON ((-122.4020153103835 48.2252163723779...
Montana4990507996866100352210119211019931102831710386561050493POLYGON ((-111.4754253002074 44.70216236909688...
Maine113275681327968132810113279751328903132778713302321335907(POLYGON ((-69.77727626137293 44.0741483685119...
North Dakota2674518684830701380722908738658754859755548755393POLYGON ((-98.73043728833767 45.93827137024809...

Plotting the data on a map is as simple as calling:

df_states.plot_bokeh(simplify_shapes=10000)

US_States_1

We also passed the optional parameter simplify_shapes (~meter) to improve plotting performance (for a reference see shapely.object.simplify). The above geolayer thus has an accuracy of about 10km.

Many keyword arguments like xlabel, ylabel, xlim, ylim, title, colormap, hovertool, zooming, panning, ... for costumizing the plot are also available for the geoplotting API and can be uses as in the examples shown above. There are however also many other options especially for plotting geodata:

  • geometry_column: Specify the column that stores the geometry-information (default: "geometry")
  • hovertool_columns: Specify column names, for which values should be shown in hovertool
  • hovertool_string: If specified, this string will be used for the hovertool (@{column} will be replaced by the value of the column for the element the mouse hovers over, see also Bokeh documentation)
  • colormap_uselog: If set True, the colormapper is using a logscale. Default: False
  • colormap_range: Specify the value range of the colormapper via (min, max) tuple
  • tile_provider: Define build-in tile provider for background maps. Possible values: None, 'CARTODBPOSITRON', 'CARTODBPOSITRON_RETINA', 'STAMEN_TERRAIN', 'STAMEN_TERRAIN_RETINA', 'STAMEN_TONER', 'STAMEN_TONER_BACKGROUND', 'STAMEN_TONER_LABELS'. Default: CARTODBPOSITRON_RETINA
  • tile_provider_url: An arbitraty tile_provider_url of the form '/{Z}/{X}/{Y}*.png' can be passed to be used as background map.
  • tile_attribution: String (also HTML accepted) for showing attribution for tile source in the lower right corner
  • tile_alpha: Sets the alpha value of the background tile between [0, 1]. Default: 1

One of the most common usage of map plots are choropleth maps, where the color of a the objects is determined by the property of the object itself. There are 3 ways of drawing choropleth maps using Pandas-Bokeh, which are described below.

Categories

This is the simplest way. Just provide the category keyword for the selection of the property column:

  • category: Specifies the column of the GeoDataFrame that should be used to draw a choropleth map
  • show_colorbar: Whether or not to show a colorbar for categorical plots. Default: True

Let us now draw the regions as a choropleth plot using the category keyword (at the moment, only numerical columns are supported for choropleth plots):

df_states.plot_bokeh(
    figsize=(900, 600),
    simplify_shapes=5000,
    category="REGION",
    show_colorbar=False,
    colormap=["blue", "yellow", "green", "red"],
    hovertool_columns=["STATE_NAME", "REGION"],
    tile_provider="STAMEN_TERRAIN_RETINA")

When hovering over the states, the state-name and the region are shown as specified in the hovertool_columns argument.

US_States_2

Dropdown

By passing a list of column names of the GeoDataFrame as the dropdown keyword argument, a dropdown menu is shown above the map. This dropdown menu can be used to select the choropleth layer by the user. :

df_states["STATE_NAME_SMALL"] = df_states["STATE_NAME"].str.lower()

df_states.plot_bokeh(
    figsize=(900, 600),
    simplify_shapes=5000,
    dropdown=["POPESTIMATE2010", "POPESTIMATE2017"],
    colormap="Viridis",
    hovertool_string="""
                        <img
                        src="https://www.states101.com/img/flags/gif/small/@STATE_NAME_SMALL.gif" 
                        height="42" alt="@imgs" width="42"
                        style="float: left; margin: 0px 15px 15px 0px;"
                        border="2"></img>
                
                        <h2>  @STATE_NAME </h2>
                        <h3> 2010: @POPESTIMATE2010 </h3>
                        <h3> 2017: @POPESTIMATE2017 </h3>""",
    tile_provider_url=r"http://c.tile.stamen.com/watercolor/{Z}/{X}/{Y}.jpg",
    tile_attribution='Map tiles by <a href="http://stamen.com">Stamen Design</a>, under <a href="http://creativecommons.org/licenses/by/3.0">CC BY 3.0</a>. Data by <a href="http://openstreetmap.org">OpenStreetMap</a>, under <a href="http://www.openstreetmap.org/copyright">ODbL</a>.'
    )

US_States_3

Using hovertool_string, one can pass a string that can contain arbitrary HTML elements (including divs, images, ...) that is shown when hovering over the geographies (@{column} will be replaced by the value of the column for the element the mouse hovers over, see also Bokeh documentation).

Here, we also used an OSM tile server with watercolor style via tile_provider_url and added the attribution via tile_attribution.

Sliders

Another option for interactive choropleth maps is the slider implementation of Pandas-Bokeh. The possible keyword arguments are here:

  • slider: By passing a list of column names of the GeoDataFrame, a slider can be used to . This dropdown menu can be used to select the choropleth layer by the user.
  • slider_range: Pass a range (or numpy.arange) of numbers object to relate the sliders values with the slider columns. By passing range(0,10), the slider will have values [0, 1, 2, ..., 9], when passing numpy.arange(3,5,0.5), the slider will have values [3, 3.5, 4, 4.5]. Default: range(0, len(slider))
  • slider_name: Specifies the title of the slider. Default is an empty string.

This can be used to display the change in population relative to the year 2010:

#Calculate change of population relative to 2010:
for i in range(8):
    df_states["Delta_Population_201%d"%i] = ((df_states["POPESTIMATE201%d"%i] / df_states["POPESTIMATE2010"]) -1 ) * 100

#Specify slider columns:
slider_columns = ["Delta_Population_201%d"%i for i in range(8)]

#Specify slider-range (Maps "Delta_Population_2010" -> 2010, 
#                           "Delta_Population_2011" -> 2011, ...):
slider_range = range(2010, 2018)

#Make slider plot:
df_states.plot_bokeh(
    figsize=(900, 600),
    simplify_shapes=5000,
    slider=slider_columns,
    slider_range=slider_range,
    slider_name="Year", 
    colormap="Inferno",
    hovertool_columns=["STATE_NAME"] + slider_columns,
    title="Change of Population [%]")

US_States_4

Plot multiple geolayers

If you wish to display multiple geolayers, you can pass the Bokeh figure of a Pandas-Bokeh plot via the figure keyword to the next plot_bokeh() call:

import geopandas as gpd
import pandas_bokeh
pandas_bokeh.output_notebook()

# Read in GeoJSONs from URL:
df_states = gpd.read_file(r"https://raw.githubusercontent.com/PatrikHlobil/Pandas-Bokeh/master/docs/Testdata/states/states.geojson")
df_cities = gpd.read_file(
    r"https://raw.githubusercontent.com/PatrikHlobil/Pandas-Bokeh/master/docs/Testdata/populated%20places/ne_10m_populated_places_simple_bigcities.geojson"
)
df_cities["size"] = df_cities.pop_max / 400000

#Plot shapes of US states (pass figure options to this initial plot):
figure = df_states.plot_bokeh(
    figsize=(800, 450),
    simplify_shapes=10000,
    show_figure=False,
    xlim=[-170, -80],
    ylim=[10, 70],
    category="REGION",
    colormap="Dark2",
    legend="States",
    show_colorbar=False,
)

#Plot cities as points on top of the US states layer by passing the figure:
df_cities.plot_bokeh(
    figure=figure,         # <== pass figure here!
    category="pop_max",
    colormap="Viridis",
    colormap_uselog=True,
    size="size",
    hovertool_string="""<h1>@name</h1>
                        <h3>Population: @pop_max </h3>""",
    marker="inverted_triangle",
    legend="Cities",
)

Multiple Geolayers

Point & Line plots:

Below, you can see an example that use Pandas-Bokeh to plot point data on a map. The plot shows all cities with a population larger than 1.000.000. For point plots, you can select the marker as keyword argument (since it is passed to bokeh.plotting.figure.scatter). Here an overview of all available marker types:

gdf = gpd.read_file(r"https://raw.githubusercontent.com/PatrikHlobil/Pandas-Bokeh/master/docs/Testdata/populated%20places/ne_10m_populated_places_simple_bigcities.geojson")
gdf["size"] = gdf.pop_max / 400000

gdf.plot_bokeh(
    category="pop_max",
    colormap="Viridis",
    colormap_uselog=True,
    size="size",
    hovertool_string="""<h1>@name</h1>
                        <h3>Population: @pop_max </h3>""",
    xlim=[-15, 35],
    ylim=[30,60],
    marker="inverted_triangle");

Pointmap

In a similar way, also GeoDataFrames with (multi)line shapes can be drawn using Pandas-Bokeh.

Colorbar formatting:

If you want to display the numerical labels on your colorbar with an alternative to the scientific format, you can pass in a one of the bokeh number string formats or an instance of one of the bokeh.models.formatters to the colorbar_tick_format argument in the geoplot

An example of using the string format argument:

df_states = gpd.read_file(r"https://raw.githubusercontent.com/PatrikHlobil/Pandas-Bokeh/master/docs/Testdata/states/states.geojson")

df_states["STATE_NAME_SMALL"] = df_states["STATE_NAME"].str.lower()

# pass in a string format to colorbar_tick_format to display the ticks as 10m rather than 1e7
df_states.plot_bokeh(
    figsize=(900, 600),
    category="POPESTIMATE2017",
    simplify_shapes=5000,    
    colormap="Inferno",
    colormap_uselog=True,
    colorbar_tick_format="0.0a")

colorbar_tick_format with string argument

An example of using the bokeh PrintfTickFormatter:

df_states = gpd.read_file(r"https://raw.githubusercontent.com/PatrikHlobil/Pandas-Bokeh/master/docs/Testdata/states/states.geojson")

df_states["STATE_NAME_SMALL"] = df_states["STATE_NAME"].str.lower()

for i in range(8):
    df_states["Delta_Population_201%d"%i] = ((df_states["POPESTIMATE201%d"%i] / df_states["POPESTIMATE2010"]) -1 ) * 100

# pass in a PrintfTickFormatter instance colorbar_tick_format to display the ticks with 2 decimal places  
df_states.plot_bokeh(
    figsize=(900, 600),
    category="Delta_Population_2017",
    simplify_shapes=5000,    
    colormap="Inferno",
    colorbar_tick_format=PrintfTickFormatter(format="%4.2f"))

colorbar_tick_format with bokeh.models.formatter_instance

Outputs, Formatting & Layouts

 

Output options

The pandas.DataFrame.plot_bokeh API has the following additional keyword arguments:

  • show_figure: If True, the resulting figure is shown (either in the notebook or exported and shown as HTML file, see Basics. If False, None is returned. Default: True
  • return_html: If True, the method call returns an HTML string that contains all Bokeh CSS&JS resources and the figure embedded in a div. This HTML representation of the plot can be used for embedding the plot in an HTML document. Default: False

If you have a Bokeh figure or layout, you can also use the pandas_bokeh.embedded_html function to generate an embeddable HTML representation of the plot. This can be included into any valid HTML (note that this is not possible directly with the HTML generated by the pandas_bokeh.output_file output option, because it includes an HTML header). Let us consider the following simple example:

#Import Pandas and Pandas-Bokeh (if you do not specify an output option, the standard is
#output_file):
import pandas as pd
import pandas_bokeh

#Create DataFrame to Plot:
import numpy as np
x = np.arange(-10, 10, 0.1)
sin = np.sin(x)
cos = np.cos(x)
tan = np.tan(x)
df = pd.DataFrame({"x": x, "sin(x)": sin, "cos(x)": cos, "tan(x)": tan})

#Make Bokeh plot from DataFrame using Pandas-Bokeh. Do not show the plot, but export
#it to an embeddable HTML string:
html_plot = df.plot_bokeh(
    kind="line",
    x="x",
    y=["sin(x)", "cos(x)", "tan(x)"],
    xticks=range(-20, 20),
    title="Trigonometric functions",
    show_figure=False,
    return_html=True,
    ylim=(-1.5, 1.5))

#Write some HTML and embed the HTML plot below it. For production use, please use
#Templates and the awesome Jinja library.
html = r"""
<script type="text/x-mathjax-config">
  MathJax.Hub.Config({tex2jax: {inlineMath: [['$','$'], ['\\(','\\)']]}});
</script>
<script type="text/javascript"
  src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML">
</script>

<h1> Trigonometric functions </h1>

<p> The basic trigonometric functions are:</p>

<p>$ sin(x) $</p>
<p>$ cos(x) $</p>
<p>$ tan(x) = \frac{sin(x)}{cos(x)}$</p>

<p>Below is a plot that shows them</p>

""" + html_plot

#Export the HTML string to an external HTML file and show it:
with open("test.html" , "w") as f:
    f.write(html)
    
import webbrowser
webbrowser.open("test.html")

This code will open up a webbrowser and show the following page. As you can see, the interactive Bokeh plot is embedded nicely into the HTML layout. The return_html option is ideal for the use in a templating engine like Jinja.

Embedded HTML

Auto Scaling Plots

For single plots that have a number of x axis values or for larger monitors, you can auto scale the figure to the width of the entire jupyter cell by setting the sizing_mode parameter.

df = pd.DataFrame(np.random.rand(10, 4), columns=['a', 'b', 'c', 'd'])

df.plot_bokeh(kind="bar", figsize=(500, 200), sizing_mode="scale_width")

Scaled Plot

The figsize parameter can be used to change the height and width as well as act as a scaling multiplier against the axis that is not being scaled.

 

Number formats

To change the formats of numbers in the hovertool, use the number_format keyword argument. For a documentation about the format to pass, have a look at the Bokeh documentation.Let us consider some examples for the number 3.141592653589793:

FormatOutput
03
0.0003.141
0.00 $3.14 $

This number format will be applied to all numeric columns of the hovertool. If you want to make a very custom or complicated hovertool, you should probably use the hovertool_string keyword argument, see e.g. this example. Below, we use the number_format parameter to specify the "Stock Price" format to 2 decimal digits and an additional $ sign.

import numpy as np

#Lineplot:
np.random.seed(42)
df = pd.DataFrame({
    "Google": np.random.randn(1000) + 0.2,
    "Apple": np.random.randn(1000) + 0.17
},
                  index=pd.date_range('1/1/2000', periods=1000))
df = df.cumsum()
df = df + 50
df.plot_bokeh(
    kind="line",
    title="Apple vs Google",
    xlabel="Date",
    ylabel="Stock price [$]",
    yticks=[0, 100, 200, 300, 400],
    ylim=(0, 400),
    colormap=["red", "blue"],
    number_format="1.00 $")

Number format

Suppress scientific notation for axes

If you want to suppress the scientific notation for axes, you can use the disable_scientific_axes parameter, which accepts one of "x", "y", "xy":

df = pd.DataFrame({"Animal": ["Mouse", "Rabbit", "Dog", "Tiger", "Elefant", "Wale"],
                   "Weight [g]": [19, 3000, 40000, 200000, 6000000, 50000000]})
p_scientific = df.plot_bokeh(x="Animal", y="Weight [g]", show_figure=False)
p_non_scientific = df.plot_bokeh(x="Animal", y="Weight [g]", disable_scientific_axes="y", show_figure=False,)
pandas_bokeh.plot_grid([[p_scientific, p_non_scientific]], plot_width = 450)

Number format

 

Dashboard Layouts

As shown in the Scatterplot Example, combining plots with plots or other HTML elements is straighforward in Pandas-Bokeh due to the layout capabilities of Bokeh. The easiest way to generate a dashboard layout is using the pandas_bokeh.plot_grid method (which is an extension of bokeh.layouts.gridplot):

import pandas as pd
import numpy as np
import pandas_bokeh
pandas_bokeh.output_notebook()

#Barplot:
data = {
    'fruits':
    ['Apples', 'Pears', 'Nectarines', 'Plums', 'Grapes', 'Strawberries'],
    '2015': [2, 1, 4, 3, 2, 4],
    '2016': [5, 3, 3, 2, 4, 6],
    '2017': [3, 2, 4, 4, 5, 3]
}
df = pd.DataFrame(data).set_index("fruits")
p_bar = df.plot_bokeh(
    kind="bar",
    ylabel="Price per Unit [€]",
    title="Fruit prices per Year",
    show_figure=False)

#Lineplot:
np.random.seed(42)
df = pd.DataFrame({
    "Google": np.random.randn(1000) + 0.2,
    "Apple": np.random.randn(1000) + 0.17
},
                  index=pd.date_range('1/1/2000', periods=1000))
df = df.cumsum()
df = df + 50
p_line = df.plot_bokeh(
    kind="line",
    title="Apple vs Google",
    xlabel="Date",
    ylabel="Stock price [$]",
    yticks=[0, 100, 200, 300, 400],
    ylim=(0, 400),
    colormap=["red", "blue"],
    show_figure=False)

#Scatterplot:
from sklearn.datasets import load_iris
iris = load_iris()
df = pd.DataFrame(iris["data"])
df.columns = iris["feature_names"]
df["species"] = iris["target"]
df["species"] = df["species"].map(dict(zip(range(3), iris["target_names"])))
p_scatter = df.plot_bokeh(
    kind="scatter",
    x="petal length (cm)",
    y="sepal width (cm)",
    category="species",
    title="Iris DataSet Visualization",
    show_figure=False)

#Histogram:
df_hist = pd.DataFrame({
    'a': np.random.randn(1000) + 1,
    'b': np.random.randn(1000),
    'c': np.random.randn(1000) - 1
},
                       columns=['a', 'b', 'c'])

p_hist = df_hist.plot_bokeh(
    kind="hist",
    bins=np.arange(-6, 6.5, 0.5),
    vertical_xlabel=True,
    normed=100,
    hovertool=False,
    title="Normal distributions",
    show_figure=False)

#Make Dashboard with Grid Layout:
pandas_bokeh.plot_grid([[p_line, p_bar], 
                        [p_scatter, p_hist]], plot_width=450)

Dashboard Layout

Using a combination of row and column elements (see also Bokeh Layouts) allow for a very easy general arrangement of elements. An alternative layout to the one above is:

p_line.plot_width = 900
p_hist.plot_width = 900

layout = pandas_bokeh.column(p_line,
                pandas_bokeh.row(p_scatter, p_bar),
                p_hist)

pandas_bokeh.show(layout)

Alternative Dashboard Layout

Release Notes

Release Notes can be found here.

Contributing to Pandas-Bokeh

If you wish to contribute to the development of Pandas-Bokeh you can follow the instructions on the CONTRIBUTING.md.

Download Details:
Author: PatrikHlobil
Source Code: https://github.com/PatrikHlobil/Pandas-Bokeh
License: MIT License

#pandas  #python #bokeh #Ploty

Keyboard: Take Full Control Of Keyboard With This Small Python Library

Hook and simulate global keyboard events on Windows and Linux.

Take full control of your keyboard with this small Python library. Hook global events, register hotkeys, simulate key presses and much more.

Features

  • Global event hook on all keyboards (captures keys regardless of focus).
  • Listen and send keyboard events.
  • Works with Windows and Linux (requires sudo), with experimental OS X support (thanks @glitchassassin!).
  • Pure Python, no C modules to be compiled.
  • Zero dependencies. Trivial to install and deploy, just copy the files.
  • Python 2 and 3.
  • Complex hotkey support (e.g. ctrl+shift+m, ctrl+space) with controllable timeout.
  • Includes high level API (e.g. record and play, add_abbreviation).
  • Maps keys as they actually are in your layout, with full internationalization support (e.g. Ctrl+ç).
  • Events automatically captured in separate thread, doesn't block main program.
  • Tested and documented.
  • Doesn't break accented dead keys (I'm looking at you, pyHook).
  • Mouse support available via project mouse (pip install mouse).

Usage

Install the PyPI package:

pip install keyboard

or clone the repository (no installation required, source files are sufficient):

git clone https://github.com/boppreh/keyboard

or download and extract the zip into your project folder.

Then check the API docs below to see what features are available.

Example

Use as library:

import keyboard

keyboard.press_and_release('shift+s, space')

keyboard.write('The quick brown fox jumps over the lazy dog.')

keyboard.add_hotkey('ctrl+shift+a', print, args=('triggered', 'hotkey'))

# Press PAGE UP then PAGE DOWN to type "foobar".
keyboard.add_hotkey('page up, page down', lambda: keyboard.write('foobar'))

# Blocks until you press esc.
keyboard.wait('esc')

# Record events until 'esc' is pressed.
recorded = keyboard.record(until='esc')
# Then replay back at three times the speed.
keyboard.play(recorded, speed_factor=3)

# Type @@ then press space to replace with abbreviation.
keyboard.add_abbreviation('@@', 'my.long.email@example.com')

# Block forever, like `while True`.
keyboard.wait()

Use as standalone module:

# Save JSON events to a file until interrupted:
python -m keyboard > events.txt

cat events.txt
# {"event_type": "down", "scan_code": 25, "name": "p", "time": 1622447562.2994788, "is_keypad": false}
# {"event_type": "up", "scan_code": 25, "name": "p", "time": 1622447562.431007, "is_keypad": false}
# ...

# Replay events
python -m keyboard < events.txt

Known limitations:

  • Events generated under Windows don't report device id (event.device == None). #21
  • Media keys on Linux may appear nameless (scan-code only) or not at all. #20
  • Key suppression/blocking only available on Windows. #22
  • To avoid depending on X, the Linux parts reads raw device files (/dev/input/input*) but this requires root.
  • Other applications, such as some games, may register hooks that swallow all key events. In this case keyboard will be unable to report events.
  • This program makes no attempt to hide itself, so don't use it for keyloggers or online gaming bots. Be responsible.
  • SSH connections forward only the text typed, not keyboard events. Therefore if you connect to a server or Raspberry PI that is running keyboard via SSH, the server will not detect your key events.

Common patterns and mistakes

Preventing the program from closing

import keyboard
keyboard.add_hotkey('space', lambda: print('space was pressed!'))
# If the program finishes, the hotkey is not in effect anymore.

# Don't do this! This will use 100% of your CPU.
#while True: pass

# Use this instead
keyboard.wait()

# or this
import time
while True:
    time.sleep(1000000)

Waiting for a key press one time

import keyboard

# Don't do this! This will use 100% of your CPU until you press the key.
#
#while not keyboard.is_pressed('space'):
#    continue
#print('space was pressed, continuing...')

# Do this instead
keyboard.wait('space')
print('space was pressed, continuing...')

Repeatedly waiting for a key press

import keyboard

# Don't do this!
#
#while True:
#    if keyboard.is_pressed('space'):
#        print('space was pressed!')
#
# This will use 100% of your CPU and print the message many times.

# Do this instead
while True:
    keyboard.wait('space')
    print('space was pressed! Waiting on it again...')

# or this
keyboard.add_hotkey('space', lambda: print('space was pressed!'))
keyboard.wait()

Invoking code when an event happens

import keyboard

# Don't do this! This will call `print('space')` immediately then fail when the key is actually pressed.
#keyboard.add_hotkey('space', print('space was pressed'))

# Do this instead
keyboard.add_hotkey('space', lambda: print('space was pressed'))

# or this
def on_space():
    print('space was pressed')
keyboard.add_hotkey('space', on_space)

# or this
while True:
    # Wait for the next event.
    event = keyboard.read_event()
    if event.event_type == keyboard.KEY_DOWN and event.name == 'space':
        print('space was pressed')

'Press any key to continue'

# Don't do this! The `keyboard` module is meant for global events, even when your program is not in focus.
#import keyboard
#print('Press any key to continue...')
#keyboard.get_event()

# Do this instead
input('Press enter to continue...')

# Or one of the suggestions from here
# https://stackoverflow.com/questions/983354/how-to-make-a-script-wait-for-a-pressed-key

API

Table of Contents

keyboard.KEY_DOWN

= 'down'

keyboard.KEY_UP

= 'up'

class keyboard.KeyboardEvent

KeyboardEvent.device

KeyboardEvent.event_type

KeyboardEvent.is_keypad

KeyboardEvent.modifiers

KeyboardEvent.name

KeyboardEvent.scan_code

KeyboardEvent.time

KeyboardEvent.to_json(self, ensure_ascii=False)

[source]

keyboard.all_modifiers

= {'alt', 'alt gr', 'ctrl', 'left alt', 'left ctrl', 'left shift', 'left windows', 'right alt', 'right ctrl', 'right shift', 'right windows', 'shift', 'windows'}

keyboard.sided_modifiers

= {'alt', 'ctrl', 'shift', 'windows'}

keyboard.version

= '0.13.5'

keyboard.is_modifier(key)

[source]

Returns True if key is a scan code or name of a modifier key.

keyboard.key_to_scan_codes(key, error_if_missing=True)

[source]

Returns a list of scan codes associated with this key (name or scan code).

keyboard.parse_hotkey(hotkey)

[source]

Parses a user-provided hotkey into nested tuples representing the parsed structure, with the bottom values being lists of scan codes. Also accepts raw scan codes, which are then wrapped in the required number of nestings.

Example:


parse_hotkey("alt+shift+a, alt+b, c")
#    Keys:    ^~^ ^~~~^ ^  ^~^ ^  ^
#    Steps:   ^~~~~~~~~~^  ^~~~^  ^

# ((alt_codes, shift_codes, a_codes), (alt_codes, b_codes), (c_codes,))

keyboard.send(hotkey, do_press=True, do_release=True)

[source]

Sends OS events that perform the given hotkey hotkey.

  • hotkey can be either a scan code (e.g. 57 for space), single key (e.g. 'space') or multi-key, multi-step hotkey (e.g. 'alt+F4, enter').
  • do_press if true then press events are sent. Defaults to True.
  • do_release if true then release events are sent. Defaults to True.

send(57)
send('ctrl+alt+del')
send('alt+F4, enter')
send('shift+s')

Note: keys are released in the opposite order they were pressed.

keyboard.press(hotkey)

[source]

Presses and holds down a hotkey (see send).

keyboard.release(hotkey)

[source]

Releases a hotkey (see send).

keyboard.is_pressed(hotkey)

[source]

Returns True if the key is pressed.


is_pressed(57) #-> True
is_pressed('space') #-> True
is_pressed('ctrl+space') #-> True

keyboard.call_later(fn, args=(), delay=0.001)

[source]

Calls the provided function in a new thread after waiting some time. Useful for giving the system some time to process an event, without blocking the current execution flow.

keyboard.hook(callback, suppress=False, on_remove=<lambda>)

[source]

Installs a global listener on all available keyboards, invoking callback each time a key is pressed or released.

The event passed to the callback is of type keyboard.KeyboardEvent, with the following attributes:

  • name: an Unicode representation of the character (e.g. "&") or description (e.g. "space"). The name is always lower-case.
  • scan_code: number representing the physical key, e.g. 55.
  • time: timestamp of the time the event occurred, with as much precision as given by the OS.

Returns the given callback for easier development.

keyboard.on_press(callback, suppress=False)

[source]

Invokes callback for every KEY_DOWN event. For details see hook.

keyboard.on_release(callback, suppress=False)

[source]

Invokes callback for every KEY_UP event. For details see hook.

keyboard.hook_key(key, callback, suppress=False)

[source]

Hooks key up and key down events for a single key. Returns the event handler created. To remove a hooked key use unhook_key(key) or unhook_key(handler).

Note: this function shares state with hotkeys, so clear_all_hotkeys affects it as well.

keyboard.on_press_key(key, callback, suppress=False)

[source]

Invokes callback for KEY_DOWN event related to the given key. For details see hook.

keyboard.on_release_key(key, callback, suppress=False)

[source]

Invokes callback for KEY_UP event related to the given key. For details see hook.

keyboard.unhook(remove)

[source]

Removes a previously added hook, either by callback or by the return value of hook.

keyboard.unhook_all()

[source]

Removes all keyboard hooks in use, including hotkeys, abbreviations, word listeners, recorders and waits.

keyboard.block_key(key)

[source]

Suppresses all key events of the given key, regardless of modifiers.

keyboard.remap_key(src, dst)

[source]

Whenever the key src is pressed or released, regardless of modifiers, press or release the hotkey dst instead.

keyboard.parse_hotkey_combinations(hotkey)

[source]

Parses a user-provided hotkey. Differently from parse_hotkey, instead of each step being a list of the different scan codes for each key, each step is a list of all possible combinations of those scan codes.

keyboard.add_hotkey(hotkey, callback, args=(), suppress=False, timeout=1, trigger_on_release=False)

[source]

Invokes a callback every time a hotkey is pressed. The hotkey must be in the format ctrl+shift+a, s. This would trigger when the user holds ctrl, shift and "a" at once, releases, and then presses "s". To represent literal commas, pluses, and spaces, use their names ('comma', 'plus', 'space').

  • args is an optional list of arguments to passed to the callback during each invocation.
  • suppress defines if successful triggers should block the keys from being sent to other programs.
  • timeout is the amount of seconds allowed to pass between key presses.
  • trigger_on_release if true, the callback is invoked on key release instead of key press.

The event handler function is returned. To remove a hotkey call remove_hotkey(hotkey) or remove_hotkey(handler). before the hotkey state is reset.

Note: hotkeys are activated when the last key is pressed, not released. Note: the callback is executed in a separate thread, asynchronously. For an example of how to use a callback synchronously, see wait.

Examples:


# Different but equivalent ways to listen for a spacebar key press.
add_hotkey(' ', print, args=['space was pressed'])
add_hotkey('space', print, args=['space was pressed'])
add_hotkey('Space', print, args=['space was pressed'])
# Here 57 represents the keyboard code for spacebar; so you will be
# pressing 'spacebar', not '57' to activate the print function.
add_hotkey(57, print, args=['space was pressed'])

add_hotkey('ctrl+q', quit)
add_hotkey('ctrl+alt+enter, space', some_callback)

keyboard.remove_hotkey(hotkey_or_callback)

[source]

Removes a previously hooked hotkey. Must be called with the value returned by add_hotkey.

keyboard.unhook_all_hotkeys()

[source]

Removes all keyboard hotkeys in use, including abbreviations, word listeners, recorders and waits.

keyboard.remap_hotkey(src, dst, suppress=True, trigger_on_release=False)

[source]

Whenever the hotkey src is pressed, suppress it and send dst instead.

Example:


remap('alt+w', 'ctrl+up')

keyboard.stash_state()

[source]

Builds a list of all currently pressed scan codes, releases them and returns the list. Pairs well with restore_state and restore_modifiers.

keyboard.restore_state(scan_codes)

[source]

Given a list of scan_codes ensures these keys, and only these keys, are pressed. Pairs well with stash_state, alternative to restore_modifiers.

keyboard.restore_modifiers(scan_codes)

[source]

Like restore_state, but only restores modifier keys.

keyboard.write(text, delay=0, restore_state_after=True, exact=None)

[source]

Sends artificial keyboard events to the OS, simulating the typing of a given text. Characters not available on the keyboard are typed as explicit unicode characters using OS-specific functionality, such as alt+codepoint.

To ensure text integrity, all currently pressed keys are released before the text is typed, and modifiers are restored afterwards.

  • delay is the number of seconds to wait between keypresses, defaults to no delay.
  • restore_state_after can be used to restore the state of pressed keys after the text is typed, i.e. presses the keys that were released at the beginning. Defaults to True.
  • exact forces typing all characters as explicit unicode (e.g. alt+codepoint or special events). If None, uses platform-specific suggested value.

keyboard.wait(hotkey=None, suppress=False, trigger_on_release=False)

[source]

Blocks the program execution until the given hotkey is pressed or, if given no parameters, blocks forever.

keyboard.get_hotkey_name(names=None)

[source]

Returns a string representation of hotkey from the given key names, or the currently pressed keys if not given. This function:

  • normalizes names;
  • removes "left" and "right" prefixes;
  • replaces the "+" key name with "plus" to avoid ambiguity;
  • puts modifier keys first, in a standardized order;
  • sort remaining keys;
  • finally, joins everything with "+".

Example:


get_hotkey_name(['+', 'left ctrl', 'shift'])
# "ctrl+shift+plus"

keyboard.read_event(suppress=False)

[source]

Blocks until a keyboard event happens, then returns that event.

keyboard.read_key(suppress=False)

[source]

Blocks until a keyboard event happens, then returns that event's name or, if missing, its scan code.

keyboard.read_hotkey(suppress=True)

[source]

Similar to read_key(), but blocks until the user presses and releases a hotkey (or single key), then returns a string representing the hotkey pressed.

Example:


read_hotkey()
# "ctrl+shift+p"

keyboard.get_typed_strings(events, allow_backspace=True)

[source]

Given a sequence of events, tries to deduce what strings were typed. Strings are separated when a non-textual key is pressed (such as tab or enter). Characters are converted to uppercase according to shift and capslock status. If allow_backspace is True, backspaces remove the last character typed.

This function is a generator, so you can pass an infinite stream of events and convert them to strings in real time.

Note this functions is merely an heuristic. Windows for example keeps per- process keyboard state such as keyboard layout, and this information is not available for our hooks.


get_type_strings(record()) #-> ['This is what', 'I recorded', '']

keyboard.start_recording(recorded_events_queue=None)

[source]

Starts recording all keyboard events into a global variable, or the given queue if any. Returns the queue of events and the hooked function.

Use stop_recording() or unhook(hooked_function) to stop.

keyboard.stop_recording()

[source]

Stops the global recording of events and returns a list of the events captured.

keyboard.record(until='escape', suppress=False, trigger_on_release=False)

[source]

Records all keyboard events from all keyboards until the user presses the given hotkey. Then returns the list of events recorded, of type keyboard.KeyboardEvent. Pairs well with play(events).

Note: this is a blocking function. Note: for more details on the keyboard hook and events see hook.

keyboard.play(events, speed_factor=1.0)

[source]

Plays a sequence of recorded events, maintaining the relative time intervals. If speed_factor is <= 0 then the actions are replayed as fast as the OS allows. Pairs well with record().

Note: the current keyboard state is cleared at the beginning and restored at the end of the function.

keyboard.add_word_listener(word, callback, triggers=['space'], match_suffix=False, timeout=2)

[source]

Invokes a callback every time a sequence of characters is typed (e.g. 'pet') and followed by a trigger key (e.g. space). Modifiers (e.g. alt, ctrl, shift) are ignored.

  • word the typed text to be matched. E.g. 'pet'.
  • callback is an argument-less function to be invoked each time the word is typed.
  • triggers is the list of keys that will cause a match to be checked. If the user presses some key that is not a character (len>1) and not in triggers, the characters so far will be discarded. By default the trigger is only space.
  • match_suffix defines if endings of words should also be checked instead of only whole words. E.g. if true, typing 'carpet'+space will trigger the listener for 'pet'. Defaults to false, only whole words are checked.
  • timeout is the maximum number of seconds between typed characters before the current word is discarded. Defaults to 2 seconds.

Returns the event handler created. To remove a word listener use remove_word_listener(word) or remove_word_listener(handler).

Note: all actions are performed on key down. Key up events are ignored. Note: word matches are case sensitive.

keyboard.remove_word_listener(word_or_handler)

[source]

Removes a previously registered word listener. Accepts either the word used during registration (exact string) or the event handler returned by the add_word_listener or add_abbreviation functions.

keyboard.add_abbreviation(source_text, replacement_text, match_suffix=False, timeout=2)

[source]

Registers a hotkey that replaces one typed text with another. For example


add_abbreviation('tm', u'™')

Replaces every "tm" followed by a space with a ™ symbol (and no space). The replacement is done by sending backspace events.

  • match_suffix defines if endings of words should also be checked instead of only whole words. E.g. if true, typing 'carpet'+space will trigger the listener for 'pet'. Defaults to false, only whole words are checked.
  • timeout is the maximum number of seconds between typed characters before the current word is discarded. Defaults to 2 seconds.

For more details see add_word_listener.

keyboard.normalize_name(name)

[source]

Given a key name (e.g. "LEFT CONTROL"), clean up the string and convert to the canonical representation (e.g. "left ctrl") if one is known.

Author: boppreh
Source Code: https://github.com/boppreh/keyboard
License: MIT License

#python #keyboard