pandas.DataFrame.from_dict : issue with dtype and columns arguments types

[mutricyl]

Describe the bug
issue with types for pandas.DataFrame.from_dict method:

• dtype is restricted to str in the stub file when pands allows for str, type and None
• columns is restricted to list of strings when pandas allows for much more (at least: str, int, float, datetime)

To Reproduce

1. minimal exemple:

import pandas as pd
import datetime

data = {'l1': [1, 2, 3],
        'l2': [4, 5, 6]}

# all of the following are accepted by pandas
# however mypy complains with the last 3
pd.DataFrame.from_dict(data, orient='index')  # OK
pd.DataFrame.from_dict(data, orient='index', dtype='float')  # OK
pd.DataFrame.from_dict(data, orient='index', columns=['a', 'b', 'c'])  # OK
pd.DataFrame.from_dict(data, orient='index', dtype=float)  # NOK
pd.DataFrame.from_dict(data, orient='index', dtype=None)  # NOK
pd.DataFrame.from_dict(data, orient='index',
                       columns=[1.0, 2, datetime.datetime.now()])  # NOK

2. type checker : mypy
3. typing errors:

from_dict_test.py:12: error: Argument "dtype" to "from_dict" of "DataFrame" has incompatible type "type[float]"; expected "str"  [arg-type]
from_dict_test.py:13: error: Argument "dtype" to "from_dict" of "DataFrame" has incompatible type "None"; expected "str"  [arg-type]
from_dict_test.py:15: error: List item 0 has incompatible type "float"; expected "str"  [list-item]
from_dict_test.py:15: error: List item 1 has incompatible type "int"; expected "str"  [list-item]
from_dict_test.py:15: error: List item 2 has incompatible type "datetime"; expected "str"  [list-item]

Please complete the following information:

• OS: Windows
• Windows 10 22H2 build: 19045.4170
• Python 3.12.2 | packaged by Anaconda, Inc. | (main, Feb 27 2024, 17:28:07) [MSC v.1916 64 bit (AMD64)] on win32
• mypy 1.9.0
• pandas-stubs 2.2.0.240218

[Dr-Irv]

Thanks for the report.

There are multiple issues with the stub for DataFrame.from_dict().

• Argument dtype should be AsTypeArg | None
• Argument columns should be Axes | None, but only if orient==Literal["index"]

So those updates could be done to the stubs, with an appropriate overload to handle the columns argument only being accepted for orient=="index" .

PR with tests welcome.

[mutricyl]

I think I can handle that, I'll give it a try anyway. Thanks for the tips