How to Declare a Constant in Python?

General Discussions
, ,
#1

How do I declare a python constant?

In Java, we do: public static final String CONST_NAME = “Name”;

#2

Well, in Python, constants are more of a convention than a strict language feature. After working with Python for quite a while, here’s how you typically declare a constant:

Using Uppercase Naming Convention In Python, constants are generally represented with all uppercase letters and underscores for clarity:

MY_CONSTANT = "Name"

Although Python doesn’t enforce immutability, this naming style signals to other developers that MY_CONSTANT is intended to remain unchanged throughout the program.

#3

Absolutely! Madhurima’s method is a great start. Now, if you’re looking to take it a step further for better organization and maintainability, here’s another approach I’ve used in projects:

Using a Class with Class Variables You can group constants together using a class, making the code more structured:

class Constants:  
    CONST_NAME = "Name"  

# Accessing the constant  
print(Constants.CONST_NAME)

This method works well when you have multiple constants to manage. The class acts like a namespace, keeping everything neatly organized.

#4

Right on, Yanisleidi! Another clever option that I find particularly useful is leveraging Python’s immutability tools. Let me share this little trick:

Using namedtuple for Constants The collections.namedtuple module creates immutable objects, which is perfect for simulating constants:

from collections import namedtuple  

Constants = namedtuple('Constants', 'CONST_NAME')  
constants = Constants(CONST_NAME="Name")  

# Accessing the constant  
print(constants.CONST_NAME)

Since namedtuple objects are immutable, you’re safeguarded against accidental modifications to the values. It’s a practical and clean approach to declaring Python constants!