Enum class in Python
Python code to demonstrate enumerations
This code defines an enumeration class Season
with four members: SPRING, SUMMER, AUTUMN, and WINTER. It showcases key properties of the enum, such as accessing an enum member, its name, and value. Additionally, it demonstrates how to obtain a list of all enum members. The output reflects the name, value, type, and a list of all Season
enum members.
Python3
from enum import Enum class Season(Enum): SPRING = 1 SUMMER = 2 AUTUMN = 3 WINTER = 4 print (Season.SPRING) print (Season.SPRING.name) print (Season.SPRING.value) print ( type (Season.SPRING)) print ( repr (Season.SPRING)) print ( list (Season)) |
Output:
Season.SPRING
SPRING
1
<enum 'Season'>
<Season.SPRING: 1>
[<Season.SPRING: 1>, <Season.SUMMER: 2>, <Season.AUTUMN: 3>, <Season.WINTER: 4>]
Accessing Modes
Enum members can be accessed in two ways:
- By value:- In this method, the value of enum member is passed.
- By name:- In this method, the name of the enum member is passed.
A separate value or name can also be accessed using the “name” or “value” keyword.
The code defines an enumeration class ‘Season'
with four members. It showcases how to access enum members by value and name. It demonstrates that you can obtain an enum member by specifying its value or name, and then access its name or value accordingly. This code provides examples for both value-based and name-based enum member access.
Python3
from enum import Enum class Season(Enum): SPRING = 1 SUMMER = 2 AUTUMN = 3 WINTER = 4 print ( "The enum member associated with value 2 is : " , Season( 2 ).name) print ( "The enum member associated with name AUTUMN is : " , Season[ 'AUTUMN' ].value) |
Output:
The enum member associated with value 2 is : SUMMER
The enum member associated with name AUTUMN is : 3
Enumerations are iterable. They can be iterated using loops
In this example, we will use for loop to print all the members of the Enum class.
The code defines an enumeration class ‘Season'
with four members. It iterates through the enum members and prints their values and names. The output displays each enum member’s value and its fully-qualified name, providing a way to work with and display enum values.
Python3
from enum import Enum class Season(Enum): SPRING = 1 SUMMER = 2 AUTUMN = 3 WINTER = 4 for season in (Season): print (season.value, "-" ,season) |
Output:
1 - Season.SPRING
2 - Season.SUMMER
3 - Season.AUTUMN
4 - Season.WINTER
Enumerations Support Hashing
In this example, we will show how users can hash the Enum class that can be used in dictionaries or sets.
This code uses the ‘enum'
module to define an enumeration class ‘Animal'
with three members: dog, cat, and lion. It then creates a dictionary di
and assigns values to it based on enum members. Finally, it checks if the dictionary matches a specific key-value pair.
Python3
import enum class Animal(enum.Enum): dog = 1 cat = 2 lion = 3 di = {} di[Animal.dog] = 'bark' di[Animal.lion] = 'roar' if di = = {Animal.dog: 'bark' , Animal.lion: 'roar' }: print ( "Enum is hashed" ) else : print ( "Enum is not hashed" ) |
Output:
Enum is hashed
Compare Enums in Python
Enumerations support two types of comparisons, that are:
- Identity:- These are checked using keywords “is” and “is not“.
- Equality :- Equality comparisons of “==” and “!=” types are also supported.
This code defines an enumeration class Animal
using the enum
module with three members: dog, cat, and lion. It then performs comparisons between enum members to check for equality and inequality.
Python3
import enum class Animal(enum.Enum): dog = 1 cat = 2 lion = 3 if Animal.dog is Animal.cat: print ( "Dog and cat are same animals" ) else : print ( "Dog and cat are different animals" ) if Animal.lion ! = Animal.cat: print ( "Lions and cat are different" ) else : print ( "Lions and cat are same" ) |
Output:
Dog and cat are different animals
Lions and cat are different
enum in Python
Enumerations in Python are implemented by using the module named “enum“. Enumerations are created using classes. Enums have names and values associated with them. Let’s cover the different concepts of Python Enum in this article.