BUG: some cases of binary arithmetic between string and timedelta raise TypeError

[sfc-gh-mvashishtha]

Pandas version checks

• I have checked that this issue has not already been reported.

• I have confirmed this bug exists on the latest version of pandas.

• I have confirmed this bug exists on the main branch of pandas.

Reproducible Example

import pandas as pd

pd.Series(pd.Timedelta(1)) + pd.Series(['1'])

Issue Description

The example above should produce pd.Series(pd.Timedelta(2)), but it raises a TypeError instead.

There are some other cases that don't work either:

• pd.Series(['1']) + pd.Series(pd.Timedelta(1))
• pd.Timedelta(1) + pd.Series(['1'])
• pd.Series(pd.Timedelta(1)) + '1'
• '1' + pd.Series(pd.Timedelta(1))
• pd.Timedelta(1) + pd.Series('1')

But some cases that do:

• pd.DataFrame(['1']) + pd.DataFrame([pd.Timedelta(1)])
• pd.DataFrame([pd.Timedelta(1)]) + pd.DataFrame(['1'])
• pd.Series(['1']) + pd.Timedelta(1)
• pd.Series('1') + pd.Timedelta(1)

Expected Behavior

Given that the Timedelta itself seems to support arithmetic with scalar strings, it seems that dataframes and series of timedelta should support arithmetic with strings or data structures containing strings.

Installed Versions

INSTALLED VERSIONS
------------------
commit                : d9cdd2ee5a58015ef6f4d15c7226110c9aab8140
python                : 3.9.18.final.0
python-bits           : 64
OS                    : Darwin
OS-release            : 23.6.0
Version               : Darwin Kernel Version 23.6.0: Mon Jul 29 21:13:04 PDT 2024; root:xnu-10063.141.2~1/RELEASE_ARM64_T6020
machine               : arm64
processor             : arm
byteorder             : little
LC_ALL                : None
LANG                  : en_US.UTF-8
LOCALE                : en_US.UTF-8

pandas                : 2.2.2
numpy                 : 1.26.3
pytz                  : 2023.3.post1
dateutil              : 2.8.2
setuptools            : 68.2.2
pip                   : 23.3.1
Cython                : None
pytest                : None
hypothesis            : None
sphinx                : None
blosc                 : None
feather               : None
xlsxwriter            : None
lxml.etree            : None
html5lib              : None
pymysql               : None
psycopg2              : None
jinja2                : None
IPython               : 8.18.1
pandas_datareader     : None
adbc-driver-postgresql: None
adbc-driver-sqlite    : None
bs4                   : None
bottleneck            : None
dataframe-api-compat  : None
fastparquet           : None
fsspec                : None
gcsfs                 : None
matplotlib            : None
numba                 : None
numexpr               : None
odfpy                 : None
openpyxl              : None
pandas_gbq            : None
pyarrow               : None
pyreadstat            : None
python-calamine       : None
pyxlsb                : None
s3fs                  : None
scipy                 : None
sqlalchemy            : None
tables                : None
tabulate              : None
xarray                : None
xlrd                  : None
zstandard             : None
tzdata                : 2023.4
qtpy                  : None
pyqt5                 : None

[sfc-gh-mvashishtha]

Also, some operators don't work, e.g. pd.Series(['1']) + pd.Timedelta(1) and pd.Series(['1']) == pd.Timedelta(1) work, but pd.Series(['1']) <= pd.Timedelta(1) does not

[rhshadrach]

Thanks for the report, confirmed on main. Further investigations and PRs to fix are welcome!

[mingjji]

take