Python Best Practices

Published: March 15, 2024

Writing clean, maintainable Python code is essential for any project's success. This guide covers essential Python best practices that will help you write better code.

Code Style and PEP 8

PEP 8 is Python's style guide. Here are some key points:

# Good
def calculate_total(items):
    return sum(item.price for item in items)

# Bad
def calculateTotal( items ):
    total=0
    for item in items:
        total+=item.price
    return total

Meaningful Variable Names

Choose descriptive names that reflect the purpose:

# Good
user_age = 25
max_retry_attempts = 3

# Bad
a = 25
n = 3

List Comprehensions

Use list comprehensions for simple transformations:

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

# Bad
squares = []
for x in range(10):
    squares.append(x**2)

Function Design

Keep functions small and focused:

# Good
def calculate_discount(price, discount_rate):
    return price * (1 - discount_rate)

# Bad
def process_order(order, user, payment, shipping):
    # Too many responsibilities
    pass

Error Handling

Use proper exception handling:

# Good
try:
    result = divide(a, b)
except ZeroDivisionError:
    print("Cannot divide by zero")
except ValueError as e:
    print(f"Invalid input: {e}")

Documentation

Write clear docstrings:

def calculate_interest(principal, rate, years):
    """
    Calculate compound interest.

    Args:
        principal (float): Initial amount
        rate (float): Annual interest rate
        years (int): Number of years

    Returns:
        float: Final amount after interest
    """
    return principal * (1 + rate) ** years

Type Hints

Use type hints for better code clarity:

from typing import List, Dict

def process_users(users: List[Dict[str, str]]) -> List[str]:
    return [user['name'] for user in users]

Testing

Write unit tests for your code:

import unittest

class TestCalculator(unittest.TestCase):
    def test_add(self):
        self.assertEqual(add(2, 3), 5)
        self.assertEqual(add(-1, 1), 0)

Best Practices Summary

1. Follow PEP 8 style guide
2. Use meaningful variable names
3. Write small, focused functions
4. Implement proper error handling
5. Document your code
6. Use type hints
7. Write tests
8. Use virtual environments
9. Keep dependencies up to date
10. Use version control

Remember, good code is not just about functionality - it's about maintainability and readability!