Best Practices in Python

Writing code that works is good – writing code that is clean, readable, and maintainable is great. Following best practices helps you avoid bugs, makes collaboration easier, and shows professionalism.

The official Python style guide is PEP 8 – we'll cover the most important parts, plus other practical tips.

Follow PEP 8 – The Style Guide

PEP 8 is the standard for Python code formatting.

• Indent with 4 spaces (no tabs)
• Maximum line length: 79 characters (88 for new code)
• Two blank lines around functions and classes
• Spaces around operators and after commas
• Use snake_case for variables and functions
• Use CapWords for class names

Naming Conventions

• Variables/functions: snake_case (my_variable)
• Constants: UPPERCASE (MAX_SIZE)
• Classes: CapWords (MyClass)
• Private: _leading_underscore (_internal)
• Choose descriptive names – avoid single letters

Write Readable Code

Clear code is better than clever code.

• Keep functions small – one responsibility
• Use meaningful names
• Add comments for complex parts
• Write docstrings for functions

Error Handling and Defensive Coding

• Use try/except for expected errors
• Validate input when possible
• Provide helpful error messages

Performance Tips

• Use list comprehensions for simple transformations
• Prefer sets for membership testing
• Use built-in functions (they're fast)
• Avoid loops when vectorized operations are possible

Quick Quiz