Check if a Value or a Name exists in an Enum in Python

# Table of Contents

1. Check if a value exists in an Enum in Python
2. Check if a name exists in an Enum in Python

# Check if a value exists in an Enum in Python

To check if a value exists in an enum in Python:

1. Use a list comprehension to get a list of all of the enum's values.
2. Use the in operator to check if the value is present in the list.
3. The in operator will return True if the value is in the list.

Copied!
from enum import Enum


class Sizes(Enum):
    SMALL = 1
    MEDIUM = 2
    LARGE = 3


values = [member.value for member in Sizes]
print(values)  # 👉️ [1, 2, 3]

if 2 in values:
    # 👇️ this runs
    print('2 is in enum values')
else:
    print('2 is NOT in enum values')

print(100 in values) # 👉️ False

We used a list comprehension to get a list of the enum's values.

The last step is to use the in operator to check if a specific value is in the list.

The in operator tests for membership. For example, x in l evaluates to True if x is a member of l, otherwise it evaluates to False.

# Checking if a value is NOT in an Enum

If you need to check if a value is not in an enum, negate the conditional with not.

Copied!
from enum import Enum


class Sizes(Enum):
    SMALL = 1
    MEDIUM = 2
    LARGE = 3


values = [member.value for member in Sizes]
print(values)  # 👉️ [1, 2, 3]

if 100 not in values:
    # 👇️ This runs
    print('100 is NOT in enum values')

You can use the same approach if you need to check if a specific name is present in an enum.

Copied!
from enum import Enum


class Sizes(Enum):
    SMALL = 1
    MEDIUM = 2
    LARGE = 3


names = [member.name for member in Sizes]

print(names)  # 👉️ ['SMALL', 'MEDIUM', 'LARGE']

if 'SMALL' in names:
    # 👇️ this runs
    print('SMALL is in enum names')

Instead of accessing the value attribute, we used the name attribute to get a list of the enum's names.

# Check if a name exists in an Enum in Python

To check if a name exists in an enum in Python:

1. Use a list comprehension to get a list of all of the enum's names.
2. Use the in operator to check if the name is present in the list.
3. The in operator will return True if the name is in the list.

Copied!
from enum import Enum


class Sizes(Enum):
    SMALL = 1
    MEDIUM = 2
    LARGE = 3


names = [member.name for member in Sizes]
print(names)  # 👉️ ['SMALL', 'MEDIUM', 'LARGE']

if 'SMALL' in names:
    # 👇️ this runs
    print('SMALL is in enum names')

We used a list comprehension to get a list of the enum's names.

The last step is to use the in operator to check if a specific name is in the list.

The in operator tests for membership. For example, x in l evaluates to True if x is a member of l, otherwise it evaluates to False.

# Check if a name exists in an Enum using the __members__ attribute

Alternatively, you could use the __members__ attribute on the class.

Copied!
from enum import Enum


class Sizes(Enum):
    SMALL = 1
    MEDIUM = 2
    LARGE = 3


# 👇️ {'SMALL': <Sizes.SMALL: 1>, 'MEDIUM': <Sizes.MEDIUM: 2>, 'LARGE': <Sizes.LARGE: 3>}
print(Sizes.__members__)

if 'SMALL' in Sizes.__members__:
    # 👇️ this runs
    print('SMALL is in enum names')

The __members__ attribute is an ordered mapping of names to members.

It contains all names defined in the enum (including the aliases).

# Additional Resources

You can learn more about the related topics by checking out the following tutorials:

• Comparing Enums or a String with an Enum in Python
• Convert an Enum to a String and vice versa in Python
• Getting Names and Values of an Enum in Python
• How to type hint Enums in Python
• How to get the value of an Entry widget in Tkinter