DEPR: is_array_like

[jbrockmendel]

is_array_like is a a one-liner return is_list_like(obj) and hasattr(obj, "dtype"). It does not recognize pyarrow objects. Often we use it when we really want something like isinstance(obj, (np.ndarray, Series, Index, ExtensionArray)), which is much more typing-friendly. We should replace its usage with these more specific checks and deprecate it.

Discussed briefly in a dev meeting a couple months ago with generally positive reception.

[rhshadrach]

which is much more typing-friendly

Would using a TypeGuard with updated logic be better? If we ever want to change what is being identified as array-like, inlining would require trying to grep through the codebase.

[jbrockmendel]

I'd be fine with that

[phofl]

sounds good to me as well

[lithomas1]

Going to tag this as good first issue.

See https://pandas.pydata.org/docs/development/contributing_codebase.html#backwards-compatibility for how to do a deprecation.

[phofl]

I might be missing something but I think we agreed on changing the implementation, not deprecating the function?