How to use Enums

A mini-guide

Apr 05, 2024

Using enums in programming is a way to define a set of named constants, which makes our code more readable and maintainable. In Python, enums were introduced in Python 3.4 through the enum module. Here's how we can use enums in Python:

Step 1: Import the Enum class

First, we need to import the Enum class from the enum module.

from enum import Enum

Step 2: Define an Enum

We can define an enum by subclassing the Enum class. Enum members are defined as class attributes.

class Color(Enum): 
    RED = 1 
    GREEN = 2 
    BLUE = 3

Step 3: Using Enum Members

We can access enum members by their name or value, and we can also iterate over them.

# Access by name
print(Color.RED)

# Access by value
print(Color(1))

# Iterate over enum members
for color in Color:
    print(color)

Enum Members

Enum members are instances of their enum class, and they're singletons. Each member has two properties: name (the name of the member) and value (the value assigned to it).

color = Color.RED
print(color.name)  # Outputs: RED
print(color.value)  # Outputs: 1

Comparing Enums

Enum members are unique and can be compared using identity (is) and equality (==) operators.

assert Color.GREEN is Color.GREEN 
assert Color.GREEN == Color.GREEN 
assert Color.GREEN is not Color.RED

In summary, using enums makes our code cleaner and more understandable, especially when dealing with a set of constants that represent a specific set of choices.

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