Make div fill height but not extend it (use scrollbar for overflow)

I have a specific layout that I want to achieve on my web page, namely: 

The layout in the above image is built with the following HTML and bootstrap classes:

        <div className="ContentWrapper d-flex mh-100 flex-row h-100">
            <div className="ContentBody flex-column flex-fill">
                <div className="ContentHeader p-3 w-100">
                    <h2>Header</h2>
                </div>
                <div className="ContentMain w-100">
                    <h2>Scrollable div, should fill height, but not more than that</h2>
                </div>
            </div>
            <div className="Sidebar h-100">
                <h2>Sidebar content</h2>
            </div>
        </div>

Relevant CSS:

.ContentWrapper {
    background-color: red;
}
.ContentBody {

background-color: blue;

}
.ContentHeader {

background-color: yellow;

}
.ContentMain {

background-color: purple;

flex: 1;

}
.Sidebar {

background-color: green;

width: 500px;

}

However, when there is too much content in the purple part, the component starts to increase in height. I wish to prevent that and have a scrollbar in the purple component.

Furthermore, I heard that some flex properties work different in Chrome and Firefox. The idea is that I want my web page to have the same behavior in both browsers.

#html #css #css3 #bootstrap

What is GEEK

Buddha Community

Why Use WordPress? What Can You Do With WordPress?

Can you use WordPress for anything other than blogging? To your surprise, yes. WordPress is more than just a blogging tool, and it has helped thousands of websites and web applications to thrive. The use of WordPress powers around 40% of online projects, and today in our blog, we would visit some amazing uses of WordPress other than blogging.
What Is The Use Of WordPress?

WordPress is the most popular website platform in the world. It is the first choice of businesses that want to set a feature-rich and dynamic Content Management System. So, if you ask what WordPress is used for, the answer is – everything. It is a super-flexible, feature-rich and secure platform that offers everything to build unique websites and applications. Let’s start knowing them:

1. Multiple Websites Under A Single Installation
WordPress Multisite allows you to develop multiple sites from a single WordPress installation. You can download WordPress and start building websites you want to launch under a single server. Literally speaking, you can handle hundreds of sites from one single dashboard, which now needs applause.
It is a highly efficient platform that allows you to easily run several websites under the same login credentials. One of the best things about WordPress is the themes it has to offer. You can simply download them and plugin for various sites and save space on sites without losing their speed.

2. WordPress Social Network
WordPress can be used for high-end projects such as Social Media Network. If you don’t have the money and patience to hire a coder and invest months in building a feature-rich social media site, go for WordPress. It is one of the most amazing uses of WordPress. Its stunning CMS is unbeatable. And you can build sites as good as Facebook or Reddit etc. It can just make the process a lot easier.
To set up a social media network, you would have to download a WordPress Plugin called BuddyPress. It would allow you to connect a community page with ease and would provide all the necessary features of a community or social media. It has direct messaging, activity stream, user groups, extended profiles, and so much more. You just have to download and configure it.
If BuddyPress doesn’t meet all your needs, don’t give up on your dreams. You can try out WP Symposium or PeepSo. There are also several themes you can use to build a social network.

3. Create A Forum For Your Brand’s Community
Communities are very important for your business. They help you stay in constant connection with your users and consumers. And allow you to turn them into a loyal customer base. Meanwhile, there are many good technologies that can be used for building a community page – the good old WordPress is still the best.
It is the best community development technology. If you want to build your online community, you need to consider all the amazing features you get with WordPress. Plugins such as BB Press is an open-source, template-driven PHP/ MySQL forum software. It is very simple and doesn’t hamper the experience of the website.
Other tools such as wpFoRo and Asgaros Forum are equally good for creating a community blog. They are lightweight tools that are easy to manage and integrate with your WordPress site easily. However, there is only one tiny problem; you need to have some technical knowledge to build a WordPress Community blog page.

4. Shortcodes
Since we gave you a problem in the previous section, we would also give you a perfect solution for it. You might not know to code, but you have shortcodes. Shortcodes help you execute functions without having to code. It is an easy way to build an amazing website, add new features, customize plugins easily. They are short lines of code, and rather than memorizing multiple lines; you can have zero technical knowledge and start building a feature-rich website or application.
There are also plugins like Shortcoder, Shortcodes Ultimate, and the Basics available on WordPress that can be used, and you would not even have to remember the shortcodes.

5. Build Online Stores
If you still think about why to use WordPress, use it to build an online store. You can start selling your goods online and start selling. It is an affordable technology that helps you build a feature-rich eCommerce store with WordPress.
WooCommerce is an extension of WordPress and is one of the most used eCommerce solutions. WooCommerce holds a 28% share of the global market and is one of the best ways to set up an online store. It allows you to build user-friendly and professional online stores and has thousands of free and paid extensions. Moreover as an open-source platform, and you don’t have to pay for the license.
Apart from WooCommerce, there are Easy Digital Downloads, iThemes Exchange, Shopify eCommerce plugin, and so much more available.

6. Security Features
WordPress takes security very seriously. It offers tons of external solutions that help you in safeguarding your WordPress site. While there is no way to ensure 100% security, it provides regular updates with security patches and provides several plugins to help with backups, two-factor authorization, and more.
By choosing hosting providers like WP Engine, you can improve the security of the website. It helps in threat detection, manage patching and updates, and internal security audits for the customers, and so much more.

Read More

#use of wordpress #use wordpress for business website #use wordpress for website #what is use of wordpress #why use wordpress #why use wordpress to build a website

Make div fill height but not extend it (use scrollbar for overflow)

I have a specific layout that I want to achieve on my web page, namely: 

The layout in the above image is built with the following HTML and bootstrap classes:

        <div className="ContentWrapper d-flex mh-100 flex-row h-100">
            <div className="ContentBody flex-column flex-fill">
                <div className="ContentHeader p-3 w-100">
                    <h2>Header</h2>
                </div>
                <div className="ContentMain w-100">
                    <h2>Scrollable div, should fill height, but not more than that</h2>
                </div>
            </div>
            <div className="Sidebar h-100">
                <h2>Sidebar content</h2>
            </div>
        </div>

Relevant CSS:

.ContentWrapper {
    background-color: red;
}
.ContentBody {

background-color: blue;

}
.ContentHeader {

background-color: yellow;

}
.ContentMain {

background-color: purple;

flex: 1;

}
.Sidebar {

background-color: green;

width: 500px;

}

However, when there is too much content in the purple part, the component starts to increase in height. I wish to prevent that and have a scrollbar in the purple component.

Furthermore, I heard that some flex properties work different in Chrome and Firefox. The idea is that I want my web page to have the same behavior in both browsers.

#html #css #css3 #bootstrap

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.

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:

• Pandas & Pyspark DataFrames
  • lineplot
  • pointplot
  • stepplot
  • scatterplot
  • barplot
  • histogram
  • areaplot
  • pieplot
  • mapplot
     
• Geoplots (Point, Line, Polygon) with GeoPandas

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

• Output options (how to get HTML representation of Bokeh plots)
• Number formats in Pandas-Bokeh (modify Hovertool number format, suppress scientific notation on axes)
• Dashboard layouts (How to layout multiple plots in rows, columns and grids)

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()

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)

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")

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)

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")

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)
    )

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)

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)")

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)

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)

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)

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")

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)

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()

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))

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")

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

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",
    )

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")

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()

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")

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()

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

df_states.plot_bokeh(simplify_shapes=10000)

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.

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>.'
    )

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 [%]")

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",
)

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");

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")

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"))

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.

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")

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:

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 $")

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)

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)

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)

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

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.

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:

• Pandas & Pyspark DataFrames
  • lineplot
  • pointplot
  • stepplot
  • scatterplot
  • barplot
  • histogram
  • areaplot
  • pieplot
  • mapplot
• Geoplots (Point, Line, Polygon) with GeoPandas

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

• Output options (how to get HTML representation of Bokeh plots)
• Number formats in Pandas-Bokeh (modify Hovertool number format, suppress scientific notation on axes)
• Dashboard layouts (How to layout multiple plots in rows, columns and grids)

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()

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)

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")

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)

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")

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)
    )

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)

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)")

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)

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)

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)

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")

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)

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()

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))

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")

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

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",
    )

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")

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()

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")

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()

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

df_states.plot_bokeh(simplify_shapes=10000)

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.

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>.'
    )

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 [%]")

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",
)

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");

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")

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"))

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.

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")

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:

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 $")

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)

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)

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)

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 

What is Ansible? A Tool to Automate Parts of Your Job

Hello everyone, today we will talk about Ansible, a fantastic software tool that allows you to automate cross-platform computer support in a simple but effective way.

Table of Contents

• What is Ansible?
• How Does Ansible Work?
• Ansible's Architecture
  • Plugins
  • Modules
  • Inventories
  • Playbook
• Benefits of Using Ansible
• Why is Ansible so important?
• How to Install and Configure Ansible on Ubuntu
• Conclusion
• References

What is Ansible?

Ansible is a tool that generates written instructions for automating IT professionals' work throughout the entire system infrastructure.

It's designed particularly for IT professionals who use it for application deployment, configuration management, intra-service orchestration, and practically anything else a systems administrator does on a weekly or daily basis.

Ansible is simple to install because it doesn't require any agent software or other security infrastructure.

While Ansible is at the cutting edge of automation, systems administration, and DevOps, it's also valuable as a tool for devs to use in their daily work.

Ansible allows you to set up not just one machine but a complete network of them all at once, and it doesn't require any programming knowledge.

How Does Ansible Work?

Ansible connects to nodes on a network (clients, servers, etc.) and then send a little program called an Ansible module to each node.

It then runs these modules through SSH and deletes them once they're done.

Your Ansible control node must have login access to the managed nodes for this interaction to work.

The most frequent method of authentication is SSH keys, but alternative methods are also allowed.

If you want to see how to install and start using Ansible, we'll cover that below.

Ansible's Architecture

Now let's take a look at Ansible's architecture and how it manages operations.

Ansible Plugins

Plugins are supplementary pieces of code that enhance functionality, and you've probably used them in many other tools and platforms. You can use Ansible's built-in plugins or create your own.

Examples are:

• Action Plugins
• Become Plugins
• Cache Plugins
• Callback Plugins
• Cliconf Plugins
• Connection Plugins
• HTTP API Plugins
• Inventory Plugins
• Lookup Plugins
• Netconf Plugins
• Tests

Ansible Modules

Modules are short programs that Ansible distributes to all nodes or remote hosts from a central control workstation. Modules control things like services and packages and can be executed via playbooks.

Ansible runs all of the modules needed to install updates or complete whatever operation is required and then removes them after they're done.

Ansible Inventories

Ansible uses an inventory file to track which hosts are part of your infrastructure and then accesses them to perform commands and playbooks.

Ansible works in parallel with various systems in your infrastructure. It accomplishes this by picking methods mentioned in Ansible's inventory file, which is saved in the host location by default.

Once the inventory is registered, you can use a simple text file to assign variables to any of the hosts, and you may retrieve inventory from a variety of sources.

Ansible Playbook

IT professionals can use Ansible playbooks to program applications, services, server nodes, and other devices without starting from scratch. Ansible playbooks, along with the conditions, variables, and tasks included within them, can be stored, shared, and reused forever.

Ansible playbooks function similarly to task manuals. They're simple YAML files, a human-readable data serialization language.

Playbooks are at the heart of what makes Ansible so popular. They specify activities that can be completed quickly without requiring the user to know or remember any specific syntax.

Benefits of Using Ansible

• Ansible is quick and easy to use, as it runs all of its operations over SSH and doesn't require the installation of any agents.
• Ansible is a free, open-source tool, and it's straightforward to set up and use: Ansible's playbooks don't require any special coding knowledge.
• Ansible can be used to perform simple tasks such as ensuring that a service is operating or rebooting from the command line without the need for configuration files.

In a more extensive or more uniform system, Ansible may be a better fit. It also provides a set of modules for managing various methods and cloud infrastructure.

Why is Ansible so important?

Modernization and digital transformation require automation that's both necessary and purposeful. We need a new management solution in today's dynamic contexts to increase speed, scale, and stability throughout IT infrastructure.

Technology is our most potent instrument for product improvement. Previously, accomplishing this required a significant amount of manual labor and intricate coordination. But today, Ansible - a simple yet powerful IT automation engine used by thousands of enterprises to simplify their setups and speed DevOps operations - is available.

How to Install Ansible on Ubuntu

Run the following commands to configure the PPA on your machine and install Ansible:

Update the repository:

sudo apt-get update

Install the software properties:

sudo apt-get install software-properties-common

And then install Ansible like this:

sudo apt-add-repository --yes --update ppa:ansible/ansible

Then run this:

sudo apt-get install ansible

You should have something similar to what is shown below:

Now that you have successfully installed Ansible, let's test if it's working by using the command below:

ansible --version

We'll use the command below to instruct Ansible to target all systems for the inventory host localhost, and we'll run the module ping from your local console (rather than ssh).

ansible all -i localhost, --connection=local -m ping

You should get a response similar to what you can see below:

How to modify the hosts that Ansible targets

We'll make changes to the host's file in /etc/ansible/hosts. This is the default file where Ansible searches for any defined hosts (and groups) where the given commands should be executed remotely.

sudo nano /etc/ansible/hosts

Add the lines below to the file and save the modifications:

[local]
localhost

Execute this command with your adjusted inventory file:

ansible all --connection=local -m ping

The response should look similar to what we have below:

How to configure a remote server

We deploy our Ansible test program to our remote server using a Digital Ocean droplet.

Use the command below to ssh into the server:

ssh username@IP_Address

Note: we have already configured an ssh key in our profile, which was selected when creating the droplet.

How to configure Ansible for a remote server

We will edit our hosts file in /etc/ansible/hosts using the command below:

sudo nano /etc/ansible/hosts

Add the lines below to the file and save the modifications:

[remote]
remote_test

[remote:vars]
ansible_host=IP_ADDRESS_OF_VIRTUAL_MACHINE
ansible_user=USERNAME

To see if Ansible can connect to your remote compute instance over SSH, let's type the following command:

ansible remote -m ping

We'll make an Ansible playbook using the command below, which is the typical way of telling Ansible which commands to run on the remote server and in what order. The playbook is written in .yml and follows a strict format.

In the official Ansible documentation, you can learn more about playbooks.

nano my-playbook.yml

Add the following code, which tells Ansible to install Docker in several steps:

---
- name: install docker
hosts: remote
become_method: sudo
become_user: root
vars: #local variables
docker_packages:
- apt-transport-https
- ca-certificates
- curl
- software-properties-common

tasks:
- name: Update apt packages
become: true #make sure you execute the task with sudo privileges
apt: #use apt module
update_cache: yes #equivalent of apt-get update

- name: Install packages needed for Docker
become: true
apt:
name: "{{ docker_packages }}" #uses our declared variable docker_packages
state: present #indicates the desired package state
force_apt_get: yes #forces to use apt-get

- name: Add official GPG key of Docker
shell: curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -

- name: Save the current Ubuntu release version into a variable
shell: lsb_release -cs
register: ubuntu_version #Output gets stored in this variable

- name: Set right Docker directory
become: true
shell: add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu {{ ubuntu_version.stdout }} stable"

- name: Update apt packages
become: true
apt:
update_cache: yes

- name: Install Docker
become: true
apt:
name: docker-ce
state: present
force_apt_get: yes

- name: Test Docker with hello world example
become: true
shell: docker run hello-world
register: hello_world_output

- name: Show output of hello word example
debug: #use debug module
msg: "Container Output: {{hello_world_output.stdout}}"

We can now execute it with the command below:

ansible-playbook my-playbook.yml -l remote

After that, we'll see some magic happen (it might take a while), and somewhere in the last debug message in our terminal, we should see "Hello from Docker!"

Conclusion

In this article, we had a detailed look into Ansible, its benefits, how it works and what it can do, its architecture, plugins, playbook, inventory, and how to configure and deploy Docker with Ansible on a remote server.

Thank you for reading!

Link: https://www.freecodecamp.org/news/what-is-ansible/

#ansible