Python enum.StrEnum Class

The enum.StrEnum class in Python’s enum module allows you to create enumerations where the members are also subclasses of str. This means that the enumeration members can be used wherever strings are expected. This is particularly useful for scenarios where you need the readability and maintainability of enumeration members combined with the functionality of strings.

Table of Contents

1. Introduction
2. enum.StrEnum Class Syntax
3. Examples
   • Basic Usage
   • Comparison with Strings
   • Using in String Operations
   • Iterating Over StrEnum Members
   • Using StrEnum in Functions
4. Real-World Use Case
5. Conclusion

Introduction

The enum.StrEnum class allows you to define enumerations where members are also subclasses of str. This makes the enumeration members compatible with string operations and comparisons, providing the benefits of both enums and strings.

enum.StrEnum Class Syntax

Here is how you define an enumeration with the enum.StrEnum class:

from enum import StrEnum

class EnumName(StrEnum):
    MEMBER1 = "value1"
    MEMBER2 = "value2"
    MEMBER3 = "value3"

Parameters:

• EnumName: The name of the enumeration.
• MEMBER: The symbolic name of the enumeration member.
• value: The string value associated with the enumeration member.

Examples

Basic Usage

Define a simple enumeration using StrEnum.

Example

from enum import StrEnum

class Day(StrEnum):
    SUNDAY = "Sunday"
    MONDAY = "Monday"
    TUESDAY = "Tuesday"
    WEDNESDAY = "Wednesday"
    THURSDAY = "Thursday"
    FRIDAY = "Friday"
    SATURDAY = "Saturday"

print(Day.MONDAY)
print(Day.MONDAY.name)
print(Day.MONDAY.value)

Output:

Monday
MONDAY
Monday

Comparison with Strings

Compare StrEnum members with strings.

Example

from enum import StrEnum

class Status(StrEnum):
    ACTIVE = "active"
    INACTIVE = "inactive"

status = Status.ACTIVE

if status == "active":
    print("Status is active")
else:
    print("Status is not active")

Output:

Status is active

Using in String Operations

Use StrEnum members in string operations.

Example

from enum import StrEnum

class Level(StrEnum):
    LOW = "low"
    MEDIUM = "medium"
    HIGH = "high"

current_level = Level.MEDIUM
message = f"The current level is {current_level.upper()}."

print(message)

Output:

The current level is MEDIUM.

Iterating Over StrEnum Members

Iterate over the members of a StrEnum enumeration.

Example

from enum import StrEnum

class Color(StrEnum):
    RED = "red"
    GREEN = "green"
    BLUE = "blue"

for color in Color:
    print(color)

Output:

red
green
blue

Using StrEnum in Functions

Use StrEnum members as function arguments and return values.

Example

from enum import StrEnum

class Direction(StrEnum):
    NORTH = "north"
    SOUTH = "south"
    EAST = "east"
    WEST = "west"

def move(direction):
    if direction == Direction.NORTH:
        return "Moving north"
    elif direction == Direction.SOUTH:
        return "Moving south"
    elif direction == Direction.EAST:
        return "Moving east"
    elif direction == Direction.WEST:
        return "Moving west"

print(move(Direction.NORTH))
print(move(Direction.WEST))

Output:

Moving north
Moving west

Real-World Use Case

Representing Configuration Options

Use a StrEnum to represent configuration options in an application, allowing for easy comparison with string values.

Example

from enum import StrEnum

class ConfigOption(StrEnum):
    DEBUG = "debug"
    INFO = "info"
    WARNING = "warning"
    ERROR = "error"

def log_message(option):
    if option == ConfigOption.DEBUG:
        return "Debugging information"
    elif option == ConfigOption.INFO:
        return "Informational message"
    elif option == ConfigOption.WARNING:
        return "Warning message"
    elif option == ConfigOption.ERROR:
        return "Error message"

print(log_message(ConfigOption.DEBUG))
print(log_message("info"))

Output:

Debugging information
Informational message

Conclusion

The enum.StrEnum class is used for creating enumerations that are also compatible with strings in Python. This allows you to leverage the readability and maintainability of enumerations while still being able to use them in string operations and comparisons. This can be especially useful in scenarios like configuration management, where you need to work with predefined sets of string values.