Python Best Practices for Clean Code

Writing Python code that is both functional and maintainable requires following established best practices. Here are some key principles to keep in mind.

Code Style: PEP 8

PEP 8 is the style guide for Python code. Following it makes your code more readable:

# Good
def calculate_total(items):
    """Calculate the total price of items."""
    return sum(item.price for item in items)

# Avoid
def calc(items):
    return sum([i.price for i in items])

Use Type Hints

Type hints improve code clarity and enable better IDE support:

from typing import List, Optional

def process_items(items: List[str]) -> Optional[int]:
    if not items:
        return None
    return len(items)

List Comprehensions vs Loops

Prefer list comprehensions for simple transformations:

# Good
squares = [x**2 for x in range(10) if x % 2 == 0]

# Less Pythonic
squares = []
for x in range(10):
    if x % 2 == 0:
        squares.append(x**2)

Virtual Environments

Always use virtual environments to manage dependencies:

python -m venv venv
source venv/bin/activate
pip install -r requirements.txt

Error Handling

Use specific exceptions and provide meaningful error messages:

try:
    result = divide(a, b)
except ZeroDivisionError:
    logger.error("Division by zero attempted")
    raise ValueError("Cannot divide by zero")

Docstrings

Document your functions and classes:

def fetch_user_data(user_id: int) -> dict:
    """
    Fetch user data from the database.

    Args:
        user_id: The unique identifier of the user

    Returns:
        Dictionary containing user information

    Raises:
        UserNotFoundError: If user doesn't exist
    """
    # Implementation here
    pass

Conclusion

Following these best practices will make your Python code more professional, maintainable, and easier for others to understand and contribute to.