How do I create a constant in Python?

In Python, there’s no built-in keyword like const (like in JavaScript or C++) to define a constant. However, by following a few conventions and best practices, you can still create variables that are treated as constants.

 1. Use All Uppercase Naming

The most common way to define a constant is by naming the variable in all uppercase letters:

PI = 3.14159

MAX_USERS = 100

• This signals to other developers that these values shouldn't be changed.
  
• It’s just a convention though—Python won't stop you from reassigning them.
  

 2. Define Constants in a Separate Module

You can also create a separate Python file, like constants.py, to store all your constants:

# constants.py

API_KEY = "your_api_key"

TIMEOUT = 30

# main.py

from constants import API_KEY

Keeps your code cleaner and easier to maintain.

 3. Use typing.Final (Python 3.8+)

If you’re using type hints, Python 3.8 introduced Final from the typing module:

from typing import Final

PI: Final = 3.14159

This tells tools like linters and type checkers that PI shouldn't be reassigned.

 Remember:

• Python won’t enforce immutability—it's up to you (and your team) to follow these conventions.
  
• Using all caps is the widely accepted standard in the Python community.
  

So, while you can't technically create a constant in Python, you can get pretty close with clear naming and good habits!