Best Practices for Pythonic Code

# Introduction ## Table of Contents [1. Comments](#comments) [2. Imports](#imports) [3. Variable Naming and Usage](#variable) [4. Constants](#constants) [5. Functions](#functions) [6. Loops and Conditional Statements](#loops) [7. Error Handling](#errors) [8. Classes](#classes) [9. Docstrings](#docstrings) [10. Testing](#testing) [11. Code Style](#style) *** <a name="comments"></a> ## Comments **Code readability should be your top priority.** - Encapsulate your code with comments. - Use the triple quotation `''' '''` or `""" """` to indicate a comment. - Explain why your code is the way it is. Comments don't describe what the code does, they *why*. - If a comment contradicts the code, both are probably wrong. <a name="imports"></a> ## Imports **Don't clutter your namespace.** - Put them on their own lines at the beginning of your code. - Add a blank line between each import. - Never import a wildcard `import *`. This litters your namespace and can lead to confusion. - Don't put code in the global area of an import file. - Put it in a `main()` function and call it with `if __name__ == '__main__':`. <a name="variable"></a> ## Variables - Use snake\_case for naming. For example, `new\_variable` is better than `newVariable`. - Make your variable names descriptive. `get\_items` is better than `gi`. - Keep functions short, and keep your variable names short. - Don't put data and functions in the same namespace. - A namespace is the area of a program where a variable is defined. For example, if a variable is defined in a function, the namespace is that function. <a name="constants"></a> ## Constants **Don't hard code numbers.** - Make it as clear as possible what these constants represent. - Constant names should be all uppercase with underscores. <a name="functions"></a> ## Functions **Code should be easy to understand.** - Use the single responsibility principle. - Each function should only do one thing. If it does multiple things, those things should be related. - Avoid side effects. - Functions should only modify local variables. - Parameters should never be modified. - Make your function names descriptive. `get\_items` is better than `gi`. - Global variables are the devil. - If you have to use them, give them a descriptive name and make sure they're necessary. <a name="loops"></a> ## Loops and Conditional Statements - Avoid hardcoded numbers. - Use snake case for your variable names. - Use a dictionary instead of a chain of if/else statements. - If statements are necessary, use them instead of `elif` statements. - Try/except statements should be used sparingly. - Use `except Exception as e` and print `e` so you can diagnose the issue. <a name="errors"></a> ## Error Handling **Code can't work right if it's broken.** - `try/except` blocks should be used sparingly to avoid hiding bugs. - Wrap the smallest possible amount of code inside a `try/except` block. - If you find yourself having to catch a `SystemExit`, you're doing something wrong. - Don't hide bugs. - If there's an error, the code should either crash or return an error code. <a name="classes"></a> ## Classes **Classes should do a single thing.** - Avoid deep inheritance. - Every class should have an `__init__` method to initialize variables. - Every class should have a `__repr__` method to provide a string representation of the class. - Use class-docstrings to document classes. - Don't class methods to print to the console. Return the value instead. <a name="docstrings"></a> ## Docstrings **Code should be easy to understand.** - Use triple quotes `''' '''` to write docstrings. - Write docstrings immediately following the function/class definition. - Briefly describe what the function/class does. - Use present tense. - Use proper grammar. - Keep docstrings concise. <a name="testing"></a> ## Testing **Code should work properly.** - Write tests immediately after writing code. - Test that the code runs successfully. - Test that the code runs unsuccessfully. - Don't test multiple things per test. <a name="style"></a> ## Code Style **Code should be readable.** - Keep lines short. - Use consistent indentation. Four spaces is the pythonic standard. - Don't mix tabs and spaces. - Use a space between operators. - Use a space after commas.

Best Practices for Pythonic Code

Comments (11) 20011 👁️