`Series.__add__` will not accept `DateOffset`

[Daverball]

series.pyi contains overloads for most datetime like series and scalar values, but not for DateOffset, even though pandas appears to support it. In most cases Timedelta for offsetting aTimestamp series is sufficient, but not when operating on calendar months/years.

To Reproduce

import pandas as pd

s = pd.date_range('2020-01-01', '2020-02-01')
s + pd.DateOffset(months=+3)

mypy will report the error (No overload variant of "__add__" of Series matches argument type "DateOffset")

• OS: Linux (OpenSUSE Tumbleweed)
• Python 3.10
• mypy 1.0.1
• pandas-stubs 2.0.1.230501

[Dr-Irv]

Need to add pd.offset.BaseOffset to addition and subtraction operators for TimestampSeries and DatetimeIndex.

[bersbersbers]

Is this example related or should I file it separately?

from __future__ import annotations

import pandas as pd

def get_series() -> pd.Series[pd.Timedelta]:
    return pd.Series(pd.Timedelta(6))

series = get_series()
series /= pd.Timedelta(3)

print(series)

It is working fine, but I am getting "Unsupported operand types for / ("Series[Timedelta]" and "Timedelta") [operator]" with pandas-stubs 2.0.3.230814

[Dr-Irv]

Is this example related or should I file it separately?

It's unrelated, but the issue here is that we have special types for series of Timedelta, Timestamp, Period, etc. That's because there is inconsistent behavior between mypy and pyright with respect to how they handle overloads with generics.

To make your code work, you can do this:

from __future__ import annotations
from typing import TYPE_CHECKING
import pandas as pd

if TYPE_CHECKING:
    from pandas.core.series import TimedeltaSeries


def get_series() -> TimedeltaSeries:
    return pd.Series(pd.Timedelta(6))


series = get_series()
series /= pd.Timedelta(3)

print(series)

[hristo-mavrodiev]

Need to add pd.offset.BaseOffset to addition and subtraction operators for TimestampSeries and DatetimeIndex.

This is something that needs to be added in the pandas-stub or something that needs to be added in the example:
s + pd.DateOffset(months=+3)

Is there any workaround to trick mypy not returning an error for this example : s + pd.DateOffset(months=+3) ?

[Dr-Irv]

This is something that needs to be added in the pandas-stub or something that needs to be added in the example:

Need a PR on pandas-stubs (with an appropriate test)

[loicdiridollou]

@Dr-Irv I believe this is actually fixed, I can't reproduce with the latest stubs (I should have fixed that in PR #1004) but please tell me if something is missing, from memory DateOffset inherits from BaseOffset.

[Dr-Irv]

@Dr-Irv I believe this is actually fixed, I can't reproduce with the latest stubs (I should have fixed that in PR #1004) but please tell me if something is missing, from memory DateOffset inherits from BaseOffset.

Agreed. Closing via #1004