Pandas version checks
Reproducible Example
df = pd.DataFrame([[4, 9]] * 3, columns=['A', 'B'])
res1 = df.groupby('A', as_index=False).apply(lambda x: x)
print("result of index name attribute with data", res1.index.names)
df = pd.DataFrame([], columns=['A', 'B'])
res2 = df.groupby('A', as_index=False).apply(lambda x: x)
print("result of index name attribute with empty data", res2.index.names)
print(f"pandas version :{pd.__version__}")Issue Description
The parameter “as_index=False” is not valid when the source DataFrame is empty.
examples:
result of index name attribute with data : [None]
result of index name attribute with empty data : ['A']
pandas version :1.3.4
result of index name attribute with data : [None]
result of index name attribute with empty data : ['A']
pandas version :1.4.3
Expected Behavior
when set “as_index=False” ,the names of index attribute of the result should be [None]
Installed Versions
Details
INSTALLED VERSIONS
commit : 945c9ed
python : 3.8.8.final.0
python-bits : 64
OS : Darwin
OS-release : 21.6.0
Version : Darwin Kernel Version 21.6.0: Sat Jun 18 17:07:25 PDT 2022; root:xnu-8020.140.41~1/RELEASE_X86_64
machine : x86_64
processor : i386
byteorder : little
LC_ALL : zh_CN.UTF-8
LANG : zh_CN.UTF-8
LOCALE : zh_CN.UTF-8
pandas : 1.3.4
numpy : 1.20.1
pytz : 2021.1
dateutil : 2.8.1
pip : 21.0.1
setuptools : 52.0.0.post20210125
Cython : 0.29.23
pytest : 6.2.3
hypothesis : None
sphinx : 4.0.1
blosc : None
feather : None
xlsxwriter : 1.3.8
lxml.etree : 4.6.3
html5lib : 1.1
pymysql : 1.0.2
psycopg2 : None
jinja2 : 2.11.3
IPython : 7.22.0
pandas_datareader: None
bs4 : 4.9.3
bottleneck : 1.3.2
fsspec : 0.9.0
fastparquet : None
gcsfs : None
matplotlib : 3.3.4
numexpr : 2.7.3
odfpy : None
openpyxl : 3.0.7
pandas_gbq : None
pyarrow : None
pyxlsb : None
s3fs : None
scipy : 1.6.2
sqlalchemy : 1.3.24
tables : 3.6.1
tabulate : None
xarray : None
xlrd : 2.0.1
xlwt : 1.3.0
numba : 0.53.1
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
Issue Description
The parameter “as_index=False” is not valid when the source DataFrame is empty.
examples:
result of index name attribute with data : [None]
result of index name attribute with empty data : ['A']
pandas version :1.3.4
result of index name attribute with data : [None]
result of index name attribute with empty data : ['A']
pandas version :1.4.3
Expected Behavior
when set “as_index=False” ,the names of index attribute of the result should be [None]
Installed Versions
Details
INSTALLED VERSIONS
commit : 945c9ed
python : 3.8.8.final.0
python-bits : 64
OS : Darwin
OS-release : 21.6.0
Version : Darwin Kernel Version 21.6.0: Sat Jun 18 17:07:25 PDT 2022; root:xnu-8020.140.41~1/RELEASE_X86_64
machine : x86_64
processor : i386
byteorder : little
LC_ALL : zh_CN.UTF-8
LANG : zh_CN.UTF-8
LOCALE : zh_CN.UTF-8
pandas : 1.3.4
numpy : 1.20.1
pytz : 2021.1
dateutil : 2.8.1
pip : 21.0.1
setuptools : 52.0.0.post20210125
Cython : 0.29.23
pytest : 6.2.3
hypothesis : None
sphinx : 4.0.1
blosc : None
feather : None
xlsxwriter : 1.3.8
lxml.etree : 4.6.3
html5lib : 1.1
pymysql : 1.0.2
psycopg2 : None
jinja2 : 2.11.3
IPython : 7.22.0
pandas_datareader: None
bs4 : 4.9.3
bottleneck : 1.3.2
fsspec : 0.9.0
fastparquet : None
gcsfs : None
matplotlib : 3.3.4
numexpr : 2.7.3
odfpy : None
openpyxl : 3.0.7
pandas_gbq : None
pyarrow : None
pyxlsb : None
s3fs : None
scipy : 1.6.2
sqlalchemy : 1.3.24
tables : 3.6.1
tabulate : None
xarray : None
xlrd : 2.0.1
xlwt : 1.3.0
numba : 0.53.1