Python 3 Cheat Sheet

Python 3 Cheat Sheet

I’ve created this Python 3 cheat sheet to help beginners remember Python language syntax.

I’ve created this Python 3 cheat sheet to help beginners remember Python language syntax.

You can also download this cheat sheet as a beautiful PDF here.

NOTE: This cheat sheet is a work in progress and is not complete yet. I’ll be adding new stuff to it over the next few weeks. So, be sure to come back and get the latest version.

If you’re starting out with Python and are looking for a fun and comprehensive tutorial, check out my YouTube tutorials. I have two Python tutorials. If you have no or little programming experience, I suggest you check out my Python tutorial for beginners. Otherwise, if you know the basics (eg variables, functions, conditional statements, loops) and are looking for a tutorial that gets straight to the point and doesn’t treat you like a beginner, check out my Python tutorial for programmers.

If you enjoy this post, please spread the love by sharing this post with others.

Variables
a = 1       # integer
b = 1.1     # float
c = 1 + 2j  # complex number (a + bi)
d = “a”     # string
e = True    # boolean (True / False)

Strings
x = “Python”
len(x)
x[0]
x[-1]
x[0:3]

# Formatted strings
name = f”{first} {last}”

# Escape sequences
\” \’ \\ \n

# String methods
x.upper()
x.lower()
x.title()
x.strip()
x.find(“p”)
x.replace(“a”, “b”)
“a” in x

Type Conversion
int(x)  
float(x) 
bool(x) 
string(x)

Falsy Values
0
“”
[]

Conditional Statements
if x == 1:  
    print(“a”)
elif x == 2:  
    print(“b”)
else:   
    print(“c”)

# Ternary operator 
x = “a” if n > 1 else “b”

# Chaining comparison operators
if 18 <= age < 65:

Loops
for n in range(1, 10): 
    print(n)

while n < 10: 
    print(n)
    n += 1

Functions
def increment(number, by=1):   
    return number + by

# Keyword arguments 
increment(2, by=1)

# Variable number of arguments 
def multiply(*numbers): 
    for number in numbers: 
        print number 

multiply(1, 2, 3, 4)

# Variable number of keyword arguments 
def save_user(**user):  
    ...

save_user(id=1, name="Mosh")

Lists
# Creating lists
letters = ["a", "b", "c"]     
matrix = [[0, 1], [1, 2]]
zeros = [0] * 5
combined = zeros + letters
numbers = list(range(20))

# Accessing items
letters = ["a", "b", "c", "d"]
letters[0]  # "a"
letters[-1] # "d"

# Slicing lists 
letters[0:3]   # "a", "b", "c"
letters[:3]    # "a", "b", "c"
letters[0:]    # "a", "b", "c", "d"
letters[:]     # "a", "b", "c", "d"
letters[::2]   # "a", "c"
letters[::-1]  # "d", "c", "b", "a" 

# Unpacking 
first, second, *other = letters 

# Looping over lists 
for letter in letters: 
    ... 

for index, letter in enumerate(letters): 
    ... 

# Adding items 
letters.append("e")
letters.insert(0, "-")

# Removing items 
letters.pop()
letters.pop(0)
letters.remove("b")
del letters[0:3]

# Finding items 
if "f" in letters: 
    letters.index("f")

# Sorting lists 
letters.sort()
letters.sort(reverse=True) 

# Custom sorting 
items = [
    ("Product1", 10),
    ("Product2", 9),
    ("Product3", 11)
]

items.sort(key=lambda item: item[1])

# Map and filter 
prices = list(map(lambda item: item[1], items))
expensive_items = list(filter(lambda item: item[1] >= 10, items))

# List comprehensions 
prices = [item[1] for item in items]
expensive_items = [item for item in items if item[1] >= 10]

# Zip function 
list1 = [1, 2, 3]
list2 = [10, 20, 30]
combined = list(zip(list1, list2))    # [(1, 10), (2, 20)]

Tuples
point = (1, 2, 3)
point(0:2)     # (1, 2)
x, y, z = point 
if 10 in point: 
    ... 

# Swapping variables 
x = 10
y = 11
x, y = y, x 

Arrays
from array import array 

numbers = array("i", [1, 2, 3])

Sets
first = {1, 2, 3, 4}
second = {1, 5}

first | second  # {1, 2, 3, 4, 5}
first & second  # {1}
first - second  # {2, 3, 4}
first ^ second  # {2, 3, 4, 5}

if 1 in first: 
    ... 

Dictionaries
point = {"x": 1, "y": 2}
point = dict(x=1, y=2)
point["z"] = 3
if "a" in point: 
    ... 
point.get("a", 0)   # 0
del point["x"]
for key, value in point.items(): 
   ... 

# Dictionary comprehensions 
values = {x: x * 2 for x in range(5)}

Generator Expressions
values = (x * 2 for x in range(10000))
len(values)  # Error
for x in values: 

Unpacking Operator
first = [1, 2, 3]
second = [4, 5, 6]
combined = [*first, "a", *second]

first = {"x": 1}
second = {"y": 2}
combined = {**first, **second}

Exceptions
# Handling Exceptions 
try: 
  …

except (ValueError, ZeroDivisionError):
  …
else: 
  # no exceptions raised
finally:
  # cleanup code 

# Raising exceptions 
if x < 1: 
    
    raise ValueError(“…”)

# The with statement 
with open(“file.txt”) as file: 
   
   … 

Classes
# Creating classes
class Point: 
    def __init__(self, x, y): 
        
        self.x = x
        self.y = y 

    def draw(self): 
        
        …

# Instance vs class attributes
class Point: 
    default_color = “red”

    def __init__(self, x, y): 
        
        self.x = x

# Instance vs class methods
class Point: 
    def draw(self): 
       
        …

    @classmethod 
    def zero(cls): 
        
        return cls(0, 0)

# Magic methods
__str__()

__eq__()
__cmp__()
... 

# Private members 
class Point: 
    def __init__(self, x): 
        
        self.__x = x

# Properties 
class Point: 
    def __init__(self, x): 
        
        self.__x = x

    @property
    def x(self):    
        return self.__x     

    @property.setter:
    def x.setter(self, value): 
        self.__x = value 


# Inheritance
class FileStream(Stream): 
    def open(self): 
       
         super().open()
         … 

# Multiple inheritance 
class FlyingFish(Flyer, Swimmer): 
    … 

# Abstract base classes
from abc import ABC, abstractmethod

class Stream(ABC): 
    @abstractmethod
    def read(self): 
        pass  

# Named tuples 
from collections import namedtuple

Point = namedtuple(“Point”, [“x”, “y”])
point = Point(x=1, y=2)

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Top Python Development Companies | Hire Python Developers

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After analyzing clients and market requirements, TopDevelopers has come up with the list of the best Python service providers. These top-rated Python developers are widely appreciated for their professionalism in handling diverse projects. When...

After analyzing clients and market requirements, TopDevelopers has come up with the list of the best Python service providers. These top-rated Python developers are widely appreciated for their professionalism in handling diverse projects. When you look for the developer in hurry you may forget to take note of review and ratings of the company's aspects, but we at TopDevelopers have done a clear analysis of these top reviewed Python development companies listed here and have picked the best ones for you.

List of Best Python Web Development Companies & Expert Python Programmers.

Python GUI Programming Projects using Tkinter and Python 3

Python GUI Programming Projects using Tkinter and Python 3

Python GUI Programming Projects using Tkinter and Python 3

Description
Learn Hands-On Python Programming By Creating Projects, GUIs and Graphics

Python is a dynamic modern object -oriented programming language
It is easy to learn and can be used to do a lot of things both big and small
Python is what is referred to as a high level language
Python is used in the industry for things like embedded software, web development, desktop applications, and even mobile apps!
SQL-Lite allows your applications to become even more powerful by storing, retrieving, and filtering through large data sets easily
If you want to learn to code, Python GUIs are the best way to start!

I designed this programming course to be easily understood by absolute beginners and young people. We start with basic Python programming concepts. Reinforce the same by developing Project and GUIs.

Why Python?

The Python coding language integrates well with other platforms – and runs on virtually all modern devices. If you’re new to coding, you can easily learn the basics in this fast and powerful coding environment. If you have experience with other computer languages, you’ll find Python simple and straightforward. This OSI-approved open-source language allows free use and distribution – even commercial distribution.

When and how do I start a career as a Python programmer?

In an independent third party survey, it has been revealed that the Python programming language is currently the most popular language for data scientists worldwide. This claim is substantiated by the Institute of Electrical and Electronic Engineers, which tracks programming languages by popularity. According to them, Python is the second most popular programming language this year for development on the web after Java.

Python Job Profiles
Software Engineer
Research Analyst
Data Analyst
Data Scientist
Software Developer
Python Salary

The median total pay for Python jobs in California, United States is $74,410, for a professional with one year of experience
Below are graphs depicting average Python salary by city
The first chart depicts average salary for a Python professional with one year of experience and the second chart depicts the average salaries by years of experience
Who Uses Python?

This course gives you a solid set of skills in one of today’s top programming languages. Today’s biggest companies (and smartest startups) use Python, including Google, Facebook, Instagram, Amazon, IBM, and NASA. Python is increasingly being used for scientific computations and data analysis
Take this course today and learn the skills you need to rub shoulders with today’s tech industry giants. Have fun, create and control intriguing and interactive Python GUIs, and enjoy a bright future! Best of Luck
Who is the target audience?

Anyone who wants to learn to code
For Complete Programming Beginners
For People New to Python
This course was designed for students with little to no programming experience
People interested in building Projects
Anyone looking to start with Python GUI development
Basic knowledge
Access to a computer
Download Python (FREE)
Should have an interest in programming
Interest in learning Python programming
Install Python 3.6 on your computer
What will you learn
Build Python Graphical User Interfaces(GUI) with Tkinter
Be able to use the in-built Python modules for their own projects
Use programming fundamentals to build a calculator
Use advanced Python concepts to code
Build Your GUI in Python programming
Use programming fundamentals to build a Project
Signup Login & Registration Programs
Quizzes
Assignments
Job Interview Preparation Questions
& Much More

Guide to Python Programming Language

Guide to Python Programming Language

Guide to Python Programming Language

Description
The course will lead you from beginning level to advance in Python Programming Language. You do not need any prior knowledge on Python or any programming language or even programming to join the course and become an expert on the topic.

The course is begin continuously developing by adding lectures regularly.

Please see the Promo and free sample video to get to know more.

Hope you will enjoy it.

Basic knowledge
An Enthusiast Mind
A Computer
Basic Knowledge To Use Computer
Internet Connection
What will you learn
Will Be Expert On Python Programming Language
Build Application On Python Programming Language