Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

BUG: Setting datetime value using dataframe masking appears to transpose the mask #46294

Open
2 of 3 tasks
agural opened this issue Mar 9, 2022 · 1 comment
Open
2 of 3 tasks
Assignees
Labels
Bug Datetime Datetime data dtype Indexing Related to indexing on series/frames, not to indexes themselves Missing-data np.nan, pd.NaT, pd.NA, dropna, isnull, interpolate

Comments

@agural
Copy link

agural commented Mar 9, 2022

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

df = pd.DataFrame([
    [0, 1],
    [0, 2]],
    index=[0, 0])
print(df)
mask = df > df.index.to_numpy().reshape(-1, 1)
print(mask)
df[mask] = np.nan
print(df)

df = pd.DataFrame([
    pd.to_datetime(["2000", "2001"]),
    pd.to_datetime(["2000", "2002"])],
    index=pd.to_datetime(["2000", "2000"]))
print(df)
mask = df > df.index.to_numpy().reshape(-1, 1)
print(mask)
df[mask] = pd.NaT
print(df)

Issue Description

The above code produces the following output:

   0  1
0  0  1
0  0  2
       0     1
0  False  True
0  False  True
   0   1
0  0 NaN
0  0 NaN
                    0          1
2000-01-01 2000-01-01 2001-01-01
2000-01-01 2000-01-01 2002-01-01
                0     1
2000-01-01  False  True
2000-01-01  False  True
                    0          1
2000-01-01 2000-01-01 2001-01-01
2000-01-01        NaT        NaT

The last outputted dataframe should have the NaT values along the second column, not the second row.

Expected Behavior

For the last dataframe above, I would expect it to look like this:

                    0   1
2000-01-01 2000-01-01 NaT
2000-01-01 2000-01-01 NaT

Installed Versions

INSTALLED VERSIONS

commit : 06d2301
python : 3.8.12.final.0
python-bits : 64
OS : Linux
OS-release : 5.11.0-1022-aws
Version : #23~20.04.1-Ubuntu SMP Mon Nov 15 14:03:19 UTC 2021
machine : x86_64
processor : x86_64
byteorder : little
LC_ALL : None
LANG : C.UTF-8
LOCALE : en_US.UTF-8

pandas : 1.4.1
numpy : 1.19.2
pytz : 2021.3
dateutil : 2.8.2
pip : 21.2.4
setuptools : 58.0.4
Cython : 0.29.25
pytest : 6.2.5
hypothesis : None
sphinx : 4.4.0
blosc : None
feather : None
xlsxwriter : 3.0.2
lxml.etree : 4.7.1
html5lib : 1.1
pymysql : None
psycopg2 : None
jinja2 : 2.11.3
IPython : 7.31.1
pandas_datareader: None
bs4 : 4.10.0
bottleneck : 1.3.2
fastparquet : None
fsspec : 2022.01.0
gcsfs : None
matplotlib : 3.5.1
numba : 0.54.1
numexpr : 2.7.3
odfpy : None
openpyxl : 3.0.9
pandas_gbq : None
pyarrow : None
pyreadstat : None
pyxlsb : None
s3fs : None
scipy : 1.6.2
sqlalchemy : 1.4.27
tables : 3.6.1
tabulate : None
xarray : None
xlrd : 2.0.1
xlwt : 1.3.0
zstandard : None

@agural agural added Bug Needs Triage Issue that has not been reviewed by a pandas team member labels Mar 9, 2022
@mroeschke mroeschke added Datetime Datetime data dtype Indexing Related to indexing on series/frames, not to indexes themselves Missing-data np.nan, pd.NaT, pd.NA, dropna, isnull, interpolate and removed Needs Triage Issue that has not been reviewed by a pandas team member labels Mar 17, 2022
@MarcSocha
Copy link

take

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
Bug Datetime Datetime data dtype Indexing Related to indexing on series/frames, not to indexes themselves Missing-data np.nan, pd.NaT, pd.NA, dropna, isnull, interpolate
Projects
None yet
Development

No branches or pull requests

3 participants