BUG: resampling error when date_range includes a single DST (original) (raw)

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• I have confirmed this bug exists on the latest version of pandas.
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Code Sample, a copy-pastable example

import pandas as pd

works as expected (note the daylight savings transitions in the head and tail)

pd.Series(1., pd.date_range('2020-03-28','2020-10-27', freq='D', tz="Europe/Amsterdam")).resample('24H').pad()

2020-03-28 00:00:00+01:00 1.0 2020-03-29 00:00:00+01:00 1.0 2020-03-30 01:00:00+02:00 1.0 2020-03-31 01:00:00+02:00 1.0 2020-04-01 01:00:00+02:00 1.0 ... 2020-10-23 01:00:00+02:00 1.0 2020-10-24 01:00:00+02:00 1.0 2020-10-25 01:00:00+02:00 1.0 2020-10-26 00:00:00+01:00 1.0 2020-10-27 00:00:00+01:00 1.0 Freq: 24H, Length: 214, dtype: float64

fails unexpectedly

pd.Series(1., pd.date_range('2020-03-28','2020-03-31', freq='D', tz="Europe/Amsterdam")).resample('24H').pad()

Traceback (most recent call last): File "", line 1, in File "/home/felix/anaconda3/envs/bvp-venv/lib/python3.6/site-packages/pandas/core/resample.py", line 453, in pad return self._upsample("pad", limit=limit) File "/home/felix/anaconda3/envs/bvp-venv/lib/python3.6/site-packages/pandas/core/resample.py", line 1092, in _upsample result.index = res_index File "/home/felix/anaconda3/envs/bvp-venv/lib/python3.6/site-packages/pandas/core/generic.py", line 5287, in setattr return object.setattr(self, name, value) File "pandas/_libs/properties.pyx", line 67, in pandas._libs.properties.AxisProperty.set File "/home/felix/anaconda3/envs/bvp-venv/lib/python3.6/site-packages/pandas/core/series.py", line 401, in _set_axis self._data.set_axis(axis, labels) File "/home/felix/anaconda3/envs/bvp-venv/lib/python3.6/site-packages/pandas/core/internals/managers.py", line 178, in set_axis f"Length mismatch: Expected axis has {old_len} elements, new " ValueError: Length mismatch: Expected axis has 4 elements, new values have 3 elements

Problem description

In my first example, resampling from an offset of 1 day to an offset of 24 hours works as expected, but only when the start and end of the DatetimeIndex share the same timezone. In my second example the date range start and ends in a different timezone due to a daylight savings transition on 29 March 2020, for which resampling to 24 hours fails.

Possibly related issue:

• BUG: Resampling a Series with a DST to 24 hours gives a different result depending on whether timedelta(hours=24) or "24H" was used. #35248

Expected Output

pd.Series(1., pd.date_range('2020-03-28','2020-03-31', freq='D', tz="Europe/Amsterdam")).resample('24H').pad()

2020-03-28 00:00:00+01:00 1.0 2020-03-29 00:00:00+01:00 1.0 2020-03-30 01:00:00+02:00 1.0 Freq: 24H, Length: 3, dtype: float64

Output of pd.show_versions()

Details

INSTALLED VERSIONS

commit : None
python : 3.7.7.final.0
python-bits : 64
OS : Linux
OS-release : 4.9.0-11-amd64
machine : x86_64
processor :
byteorder : little
LC_ALL : None
LANG : en_US.UTF-8
LOCALE : en_US.UTF-8
pandas : 1.0.5
numpy : 1.19.0
pytz : 2020.1
dateutil : 2.8.1
pip : 20.1.1
setuptools : 47.3.1.post20200622
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 : None
pandas_datareader: None
bs4 : None
bottleneck : None
fastparquet : None
gcsfs : None
lxml.etree : None
matplotlib : None
numexpr : None
odfpy : None
openpyxl : None
pandas_gbq : None
pyarrow : None
pytables : None
pytest : None
pyxlsb : None
s3fs : None
scipy : None
sqlalchemy : None
tables : None
tabulate : None
xarray : None
xlrd : None
xlwt : None
xlsxwriter : None
numba : None