Pandas Use an enum for infer_dtype return values?

While working in https://github.com/pandas-dev/pandas/pull/29799, it was quite hard to add a new return value from lib.infer_dtype. There are many places where we do something like

inferred_dtype = lib.infer_dtype(values)

if inferred_dtype == "string":
    ...

if inferred_dtype in {"datetime", "integer"}
    ...

It was hard to grep for these. Could we instead define an enum

class InferredType(enum.Enum):
    STRING: "string"
    INTEGER: "intger"
    MIXED_INTEGER: "mixed-integer"
    ...

And then return InferredType.INTEGER, and update all our checks for

if inferred_dtype == InferredType.INTEGER

I think this should be entirely backwards compatible, since we're still just returning the string.

Comment From: jreback

yep this is generally a good idea

Comment From: alimcmaster1

Sounds good this would be neat.

I guess the check would be

if inferred_dtype == InferredType.INTEGER.value

I can potentially take a look at this is we feel its worth doing.

Comment From: theoniko

Hello @TomAugspurger, @mroeschke, @alimcmaster1, @jreback Could you please have a look to https://github.com/pandas-dev/pandas/pull/52517 and give me feeback pr is in the right direction? I am also not sure about https://github.com/pandas-dev/pandas/blob/b1dbbe08fd958afd8df4bbec437215daf2773c06/pandas/_libs/lib.pyx#L1522?

Comment From: theoniko

Could somebody have a look to my pr and give feedback?