python - Serialising an Enum member to JSON

Question

How do I serialise a Python Enum member to JSON, so that I can deserialise the resulting JSON back into a Python object?

For example, this code:

from enum import Enum    
import json

class Status(Enum):
    success = 0

json.dumps(Status.success)

results in the error:

TypeError: <Status.success: 0> is not JSON serializable

How can I avoid that?

Answer 1

I know this is old but I feel this will help people. I just went through this exact problem and discovered if you're using string enums, declaring your enums as a subclass of str works well for almost all situations:

import json
from enum import Enum

class LogLevel(str, Enum):
    DEBUG = 'DEBUG'
    INFO = 'INFO'

print(LogLevel.DEBUG)
print(json.dumps(LogLevel.DEBUG))
print(json.loads('"DEBUG"'))
print(LogLevel('DEBUG'))

Will output:

LogLevel.DEBUG
"DEBUG"
DEBUG
LogLevel.DEBUG

As you can see, loading the JSON outputs the string DEBUG but it is easily castable back into a LogLevel object. A good option if you don't want to create a custom JSONEncoder.