Best Practices

Relax. We'll talk through this in plain words — no textbook voice.

Python Best Practices are guidelines for writing clean, maintainable, and efficient code.

📚 PEP 8 Style Guide:

• 4 spaces for indentation

• Max line length: 79 characters

• snake_case for variables

• PascalCase for classes

✨ Best Practices:

• Use meaningful variable names

• Write docstrings

• Don't repeat yourself (DRY)

• Keep functions small and focused

• Use list comprehensions

• Handle exceptions properly

• Use virtual environments

⚠️ Common Pitfalls:

• Mutable default arguments

• Not closing files

• Comparing with == for None

• Using global variables

python

# Good practices example

def calculate_tax(income, tax_rate=0.2):
    """
    Calculate tax based on income and tax rate.
    
    Args:
        income (float): Annual income
        tax_rate (float): Tax rate (default: 0.2)
    
    Returns:
        float: Tax amount
    """
    if income < 0:
        raise ValueError("Income cannot be negative")
    
    return income * tax_rate

# Use 'is' for None comparison
value = None
if value is None:
    print("Value is None")

# List comprehension instead of loops
squares = [x**2 for x in range(10)]

print(f"Tax: {calculate_tax(50000)}")

You should see

Value is None Tax: 10000.0