PEP 8

What is PEP 8?

PEP 8 is a style guide for writing Python code. It outlines conventions and best practices that ensure:

1. Consistency: Code looks uniform, making it easier to read and understand.
2. Readability: It emphasizes writing clean and readable code.
3. Community Standards: Encourages practices accepted and expected by the Python community.

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Purpose of PEP 8

• Help Python developers write more understandable code.
• Ensure consistent style across Python codebases.
• Make it easier for newcomers to read and contribute to existing Python projects.

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Key PEP 8 Guidelines

1. Indentation:

   • Use 4 spaces per indentation level.
   • Never mix tabs and spaces.

   def example_function():
       for i in range(10):
           print(i)  # 4 spaces used for indentation
    

2. Line Length:

   • Limit lines to a maximum of 79 characters.
   • For longer blocks of text (like comments), limit them to 72 characters.

   # This is a very long comment. To improve readability, limit lines
   # to 72 characters when writing block comments like this.
    

3. Blank Lines:

   • Use blank lines to separate functions, classes, and blocks of code.

   class Example:
       def method_one(self):
           pass
    
       def method_two(self):
           pass
    

4. Imports:

   • Place all imports at the top of the file.
   • Group imports in the following order:
     1. Standard library imports.
     2. Third-party library imports.
     3. Local application/library-specific imports.

   # Example:
   import os
   import sys
    
   import numpy as np
    
   from myproject import mymodule
    

5. Whitespace:

   • Avoid extra spaces in expressions or statements.

   # Correct:
   x = 1 + 2
   y = (a, b)
    
   # Incorrect:
   x = 1  + 2
   y = ( a, b )
    
   # Also incorrect:
   x    = 1 + 2
    
    

6. Naming Conventions:

   • Variable and function names: snake_case
   • Class names: PascalCase
   • Constants: UPPER_CASE

   # Example:
   class MyClass:
       def my_method(self):
           my_variable = 42
    

7. Comments:

   • Comments should be concise and relevant.
   • Use complete sentences when explaining complex code.

   # Correct:
   # This function calculates the square of a number.
   def square(n):
       return n ** 2
    
   # Incorrect:
   # function calc square
   def square(n):
       return n ** 2
    

8. Docstrings:

   • Use triple quotes for docstrings, and include a description for classes, functions, and modules.

   def add(a, b):
       """Return the sum of a and b."""
       return a + b
    

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