BUG: bin edges incorrect in resample for 'B' and 'C' · Issue #55281 · pandas-dev/pandas (original) (raw)

Pandas version checks

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

In [52]: import pandas as pd ...: dti = pd.date_range(start="2020-01-31", freq="1min", periods=6000) ...: df = pd.DataFrame({'ts': dti}, index=dti) ...: grouped = df.resample('D', closed='right') ...: grouped.last() Out[52]: ts 2020-01-30 2020-01-31 00:00:00 2020-01-31 2020-02-01 00:00:00 2020-02-01 2020-02-02 00:00:00 2020-02-02 2020-02-03 00:00:00 2020-02-03 2020-02-04 00:00:00 2020-02-04 2020-02-04 03:59:00

In [53]: import pandas as pd ...: dti = pd.date_range(start="2020-01-31", freq="1min", periods=6000) ...: df = pd.DataFrame({'ts': dti}, index=dti) ...: grouped = df.resample('B', closed='right') ...: grouped.last() Out[53]: ts 2020-01-30 2020-01-31 23:59:00 2020-01-31 2020-02-03 23:59:00 2020-02-03 2020-02-04 03:59:00

Issue Description

In the above, 'D' ('day'), the last point is at midnight of the following day

But for 'B', it's one minute before midnight of the following day

This is due to this 11-year-old hack

7fb453a

Expected Behavior

For the second one, I think:

                        ts

2020-01-30 2020-01-31 00:00:00 2020-01-31 2020-02-03 00:00:00 2020-02-03 2020-02-04 00:00:00

Installed Versions

INSTALLED VERSIONS

commit : e86ed37
python : 3.10.12.final.0
python-bits : 64
OS : Linux
OS-release : 5.10.102.1-microsoft-standard-WSL2
Version : #1 SMP Wed Mar 2 00:30:59 UTC 2022
machine : x86_64
processor : x86_64
byteorder : little
LC_ALL : None
LANG : en_GB.UTF-8
LOCALE : en_GB.UTF-8

pandas : 2.1.1
numpy : 1.25.1
pytz : 2023.3
dateutil : 2.8.2
setuptools : 67.6.1
pip : 23.1.2
Cython : None
pytest : 7.3.1
hypothesis : 6.82.4
sphinx : None
blosc : None
feather : None
xlsxwriter : None
lxml.etree : None
html5lib : None
pymysql : None
psycopg2 : None
jinja2 : 3.1.2
IPython : 8.13.2
pandas_datareader : None
bs4 : 4.12.2
bottleneck : None
dataframe-api-compat: None
fastparquet : 2023.7.0
fsspec : 2023.6.0
gcsfs : None
matplotlib : 3.7.1
numba : None
numexpr : None
odfpy : None
openpyxl : None
pandas_gbq : None
pyarrow : 12.0.1
pyreadstat : None
pyxlsb : None
s3fs : None
scipy : 1.11.0
sqlalchemy : 2.0.20
tables : None
tabulate : None
xarray : None
xlrd : None
zstandard : None
tzdata : 2023.3
qtpy : None
pyqt5 : None
None