[SOLVED] Casting int to valid enum member causes ValueError in Python

Casting int to valid enum member causes ValueError in Python

**Hi.

Coming from a C# background and relatively new to python, I'm struggling with something that should be pretty straightforward (I think).

I have an enum declared as follows:

from enum import Enum

class MessageRole(Enum):
    SYSTEM = 1,
    ASSISTANT = 2,
    USER = 3,
    FUNCTION = 4,
    TOOL = 5

I'm trying to cast an integer to a specific enum value using the following code:

role: MessageRole = MessageRole(1)

...which produces the following error:

An error occurred: 1 is not a valid MessageRole

I'm running Python 3.12.10 in VS Code.

What am I doing wrong?

Solution

The issue is due to the trailing commas you added in your enum value. Python sees the value with trailing commas as tuples. To resolve the issue:

from enum import Enum


class MessageRole(Enum):
    SYSTEM = 1
    ASSISTANT = 2
    USER = 3
    FUNCTION = 4
    TOOL = 5

role: MessageRole = MessageRole(1)
print(role)