π Playground and cheatsheet for learning Python. Collection of Python scripts that are split by topics and contain code examples with explanations.
Playground and Cheatsheet for Learning Python
πΊπ¦ UKRAINE IS BEING ATTACKED BY RUSSIAN ARMY. CIVILIANS ARE GETTING KILLED. RESIDENTIAL AREAS ARE GETTING BOMBED.
- Help Ukraine via:
- Serhiy Prytula Charity Foundation
- Come Back Alive Charity Foundation
- National Bank of Ukraine
- More info on war.ukraine.ua and MFA of Ukraine
This is a collection of Python scripts that are split by topics and containcode examples with explanations, different use cases and links to further readings.
Read this in: PortuguΓͺs, EspaΓ±ol, Traditional Chinese, Π£ΠΊΡΠ°ΡΠ½ΡΡΠΊΠ°.
It is a playground because you may change or add the code to see how it works and test it out using assertions. It also allows you to lint the code you've wrote and check if it fits to Python code style guide. Altogether it might make your learning process to be more interactive and it might help you to keep code quality pretty high from very beginning.
It is a cheatsheet because you may get back to these code examples once you want to recap the syntax of standard Python statements and constructions. Also because the code is full of assertions you'll be able to see expected functions/statements output right away without launching them.
You might also be interested in π€ Interactive Machine Learning Experiments_
How to Use This Repository
Each Python script in this repository has the following structure:
"""Lists <--- Name of the topic here
@see: https://www.learnpython.org/en/Lists <-- Link to further readings goes here
Here might go more detailed explanation of the current topic (i.e. general info about Lists). """
def testlisttype(): """Explanation of sub-topic goes here. Each file contains test functions that illustrate sub-topics (i.e. lists type, lists methods). """ # Here is an example of how to build a list. <-- Comments here explain the action squares = [1, 4, 9, 16, 25] # Lists can be indexed and sliced. # Indexing returns the item. assert squares[0] == 1 # <-- Assertions here illustrate the result. # Slicing returns a new list. assert squares[-3:] == [9, 16, 25] # <-- Assertions here illustrate the result.
So normally you might want to do the following:
- Find the topic you want to learn or recap.
- Read comments and/or documentation that is linked in each script's docstring (as in example above).
- Look at code examples and assertions to see usage examples and expected output.
- Change code or add new assertions to see how things work.
- Run tests and lint the code to see if it work and is
Table of Contents
- Getting Started
- Operators
+, -, /, //, %, *)
- Bitwise Operators (&, |, ^, >>, <<, ~)
- Assignment Operators (=, +=, -=, /=, //= etc.)
- Comparison Operator (==, !=, >, <, >=, <=)
- Logical Operators (and, or, not)
- Identity Operators (is, is not)
- Membership Operators (in, not in)
- Data Types
- Control Flow
if statement
- The for statement (and range() function)
- The while statement
- The try statements
- The break statement
- The continue statement
- Functions
def and return statements)
- Scopes of Variables Inside Functions (global and nonlocal statements)
- Default Argument Values
- Keyword Arguments
- Arbitrary Argument Lists
- Unpacking Argument Lists (* statements)
- Lambda Expressions (lambda statement)
- Documentation Strings
- Function Annotations
- Function Decorators
- Classes
class statement)
- Class Objects
- Instance Objects
- Method Objects
- Class and Instance Variables
- Inheritance
- Multiple Inheritance
- Modules
import statement)
- Packages
- Errors and Exceptions
try statement)
- Raising Exceptions (raise statement)
- Files
with statement)
- Methods of File Objects
- Additions
pass statement
- Generators (yield statement)
- Brief Tour of the Standard Libraries
json library)
- File Wildcards (glob library)
- String Pattern Matching (re library)
- Mathematics (math, random, statistics libraries)
- Dates and Times (datetime library)
- Data Compression (zlib library)
- User input
input statement)
Prerequisites
Installing Python
Make sure that you have Python3 installed on your machine.
You might want to use venv standard Python library to create virtual environments and have Python, pip and all dependent packages to be installed and served from the local project directory to avoid messing with system wide packages and their versions.
Depending on your installation you might have access to Python3 interpreter either by running python or python3. The same goes for pip package manager - it may be accessible either by running pip or pip3.
You may check your Python version by running:
python --versionNote that in this repository whenever you see python it will be assumed that it is Python 3.
Installing dependencies
Install all dependencies that are required for the project by running:
pip install -r requirements.txtTesting the Code
Tests are made using pytest framework.
You may add new tests for yourself by adding files and functions with test_ prefix (i.e. testtopic.py with def testsub_topic() function inside).
To run all the tests please execute the following command from the project root folder:
pytestTo run specific tests please execute:
pytest ./path/to/the/test_file.pyLinting the Code
Linting is done using pylint and flake8 libraries.
PyLint
To check if the code is written with respect to PEP 8 style guide please run:
pylint ./src/In case if linter will detect error (i.e. missing-docstring) you may want to read more about specific error by running:
pylint --help-msg=missing-docstringFlake8
To check if the code is written with respect to PEP 8 style guide please run:
flake8 ./srcOr if you want to have more detailed output you may run:
flake8 ./src --statistics --show-source --count
