Variables and Data Types

Variable Naming Conventions

Python’s variable naming follows specific conventions for readability and maintainability. Inconsistent naming can lead to errors and make code harder to understand.

Key Principles:

• Use descriptive names: Names should clearly indicate the variable’s purpose. user_age is better than x or a.

• Lowercase with underscores: For variables, use lowercase letters separated by underscores (snake_case). e.g., total_price, customer_name.

• Constants: For constants (values that don’t change), use all uppercase with underscores. e.g., MAX_VALUE, PI.

• Avoid reserved keywords: Don’t use Python’s reserved keywords (e.g., if, else, for, while, import, def) as variable names.

• Be consistent: Maintain a consistent style throughout your code.

Examples:

# Good examples
user_name = "Alice"
product_price = 99.99
is_active = True
MAX_ATTEMPTS = 3

# Bad examples
usrnm = "Bob"       # Too short and cryptic
productPrice = 10  # Inconsistent casing
2items = 2        # Starts with a number (invalid)
if = 1             # Uses a reserved keyword (invalid)

Further Notes:

• Data Types (Understanding Data Types helps in choosing appropriate variable names.)
• Code Style Guides (PEP 8 provides detailed guidelines on Python style, including variable naming.)

Example of referencing another note:

For a more in-depth explanation on how to choose effective variable names, refer to Choosing Descriptive Variable Names.