Open
Description
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({'a': [1,2,3], 'b':[4,5,6]})
df.at[slice(0, 1, None), 'c'] = 7 # GOOD
df.at[slice(0, 1, None), 'c'] = 8 # BAD
```python-traceback
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/local/Caskroom/miniconda/4.6.14/miniconda3/envs/test/lib/python3.9/site-packages/pandas/core/indexing.py", line 2281, in __setitem__
return super().__setitem__(key, value)
File "/usr/local/Caskroom/miniconda/4.6.14/miniconda3/envs/test/lib/python3.9/site-packages/pandas/core/indexing.py", line 2236, in __setitem__
self.obj._set_value(*key, value=value, takeable=self._takeable)
File "/usr/local/Caskroom/miniconda/4.6.14/miniconda3/envs/test/lib/python3.9/site-packages/pandas/core/frame.py", line 3869, in _set_value
loc = self.index.get_loc(index)
File "/usr/local/Caskroom/miniconda/4.6.14/miniconda3/envs/test/lib/python3.9/site-packages/pandas/core/indexes/range.py", line 388, in get_loc
self._check_indexing_error(key)
File "/usr/local/Caskroom/miniconda/4.6.14/miniconda3/envs/factor/lib/python3.9/site-packages/pandas/core/indexes/base.py", line 5637, in _check_indexing_error
raise InvalidIndexError(key)
pandas.errors.InvalidIndexError: slice(0, 1, None)
### Issue Description
It shows us create a dataframe, then try add a column c and assign some value to special index using **.at[]** operation.
first time it is GOOD, but then next time i try to fill the other value even in the same index we got an InvalidIndexError.
### Expected Behavior
no errors, and result should be:
a b c
0 1 4 8.0
1 2 5 8.0
2 3 6 NaN
### Installed Versions
<details>
INSTALLED VERSIONS
------------------
commit : e8093ba372f9adfe79439d90fe74b0b5b6dea9d6
python : 3.9.1.final.0
python-bits : 64
OS : Darwin
OS-release : 20.6.0
Version : Darwin Kernel Version 20.6.0: Wed Jun 23 00:26:31 PDT 2021; root:xnu-7195.141.2~5/RELEASE_X86_64
machine : x86_64
processor : i386
byteorder : little
LC_ALL : None
LANG : None
LOCALE : None.UTF-8
pandas : 1.4.3
numpy : 1.21.2
pytz : 2021.3
dateutil : 2.8.2
setuptools : 58.0.4
pip : 21.2.4
Cython : 0.29.24
pytest : None
hypothesis : None
sphinx : None
blosc : None
feather : None
xlsxwriter : None
lxml.etree : None
html5lib : None
pymysql : 1.0.2
psycopg2 : None
jinja2 : 3.0.2
IPython : 7.28.0
pandas_datareader: None
bs4 : 4.10.0
bottleneck : 1.3.4
brotli : 1.0.9
fastparquet : None
fsspec : 2021.10.1
gcsfs : None
markupsafe : 2.0.1
matplotlib : 3.5.1
numba : 0.55.1
numexpr : 2.8.1
odfpy : None
openpyxl : 3.0.9
pandas_gbq : None
pyarrow : 4.0.1
pyreadstat : None
pyxlsb : None
s3fs : None
scipy : 1.7.1
snappy : None
sqlalchemy : 1.3.24
tables : 3.7.0
tabulate : 0.8.9
xarray : None
xlrd : 2.0.1
xlwt : None
zstandard : None
</details>