Python – Variable Names

✅ Python Variable Naming Rules & Guidelines (20 Total)🧩 Basic Rules (Syntax Requirements):

1. Must begin with a letter (a–z, A–Z) or an underscore _.
   – my_var, _value ✅
2. Cannot begin with a digit.
   – 1value ❌ (Invalid)
3. Can include letters, digits, and underscores only.
   – user1, score_2 ✅
4. Cannot contain spaces.
   – user name ❌ → Use user_name ✅
5. Cannot contain special characters like @, #, $, %, etc.
   – name$ ❌
6. Cannot be a Python keyword.
   – class, if, while ❌ → Reserved words
7. Case-sensitive.
   – age and Age are two different variables.
8. No punctuation allowed (e.g., !, ?, .)
   – price! ❌
9. Can be of any length.
   – But very long names are discouraged.
10. Do not use dashes -
    – my-variable ❌ → Use my_variable ✅

🧠 Best Practices (Good Naming Habits):

11. Use descriptive names.
    – total_amount is better than ta.
12. Use lowercase letters (snake_case) for regular variables.
    – user_age ✅
13. Use all capital letters for constants (by convention).
    – MAX_SPEED = 100
14. Avoid single-character names (unless for short loops).
    – Use index instead of i, unless in a loop.
15. Do not use names that are similar to built-in functions.
    – Avoid naming a variable list, str, int, etc.
16. Prefix private/internal-use variables with an underscore _.
    – _internal_value
17. Avoid using double underscores unless you're defining special methods.
    – __init__ is used by Python internally.
18. Use consistent naming style throughout your code.
    – Stick to snake_case, don’t mix with camelCase.
19. Avoid acronyms or shorthand unless widely known.
    – user_id is better than uid.
20. Comment your variables if their purpose isn't obvious.
    – Helps improve code readability and maintainability.

Do it