-
[x] I have checked that this issue has not already been reported.
-
[x] I have confirmed this bug exists on the latest version of pandas.
-
[ ] (optional) I have confirmed this bug exists on the master branch of pandas.
Note: Please read this guide detailing how to provide the necessary information for us to reproduce your bug.
Code Sample, a copy-pastable example
import pandas as pd
s = pd.Series(["a", "a", "b"]).astype("category")
s.map({"a": (1, 2), "b": (3, 4)})
Problem description
NotImplementedError: isna is not defined for MultiIndex
Full traceback
---------------------------------------------------------------------------
NotImplementedError Traceback (most recent call last)
<ipython-input-209-1bb58119eb75> in <module>
1 import pandas as pd
2 s = pd.Series(["a", "a", "b"]).astype("category")
----> 3 s.map({"a": (1, 2), "b": (3, 4)})
~/miniconda3/envs/seaborn-py38-latest/lib/python3.8/site-packages/pandas/core/series.py in map(self, arg, na_action)
3907 dtype: object
3908 """
-> 3909 new_values = super()._map_values(arg, na_action=na_action)
3910 return self._constructor(new_values, index=self.index).__finalize__(
3911 self, method="map"
~/miniconda3/envs/seaborn-py38-latest/lib/python3.8/site-packages/pandas/core/base.py in _map_values(self, mapper, na_action)
901 # "Union[ExtensionArray, Any]" has no attribute "map"
902 # [union-attr]
--> 903 return self._values.map(mapper) # type: ignore[union-attr]
904
905 values = self._values
~/miniconda3/envs/seaborn-py38-latest/lib/python3.8/site-packages/pandas/core/arrays/categorical.py in map(self, mapper)
1196 new_categories = self.categories.map(mapper)
1197 try:
-> 1198 return self.from_codes(
1199 self._codes.copy(), categories=new_categories, ordered=self.ordered
1200 )
~/miniconda3/envs/seaborn-py38-latest/lib/python3.8/site-packages/pandas/core/arrays/categorical.py in from_codes(cls, codes, categories, ordered, dtype)
567 Categories (2, object): ['a' < 'b']
568 """
--> 569 dtype = CategoricalDtype._from_values_or_dtype(
570 categories=categories, ordered=ordered, dtype=dtype
571 )
~/miniconda3/envs/seaborn-py38-latest/lib/python3.8/site-packages/pandas/core/dtypes/dtypes.py in _from_values_or_dtype(cls, values, categories, ordered, dtype)
271 # Note: This could potentially have categories=None and
272 # ordered=None.
--> 273 dtype = CategoricalDtype(categories, ordered)
274
275 return dtype
~/miniconda3/envs/seaborn-py38-latest/lib/python3.8/site-packages/pandas/core/dtypes/dtypes.py in __init__(self, categories, ordered)
158
159 def __init__(self, categories=None, ordered: Ordered = False):
--> 160 self._finalize(categories, ordered, fastpath=False)
161
162 @classmethod
~/miniconda3/envs/seaborn-py38-latest/lib/python3.8/site-packages/pandas/core/dtypes/dtypes.py in _finalize(self, categories, ordered, fastpath)
312
313 if categories is not None:
--> 314 categories = self.validate_categories(categories, fastpath=fastpath)
315
316 self._categories = categories
~/miniconda3/envs/seaborn-py38-latest/lib/python3.8/site-packages/pandas/core/dtypes/dtypes.py in validate_categories(categories, fastpath)
505 if not fastpath:
506
--> 507 if categories.hasnans:
508 raise ValueError("Categorical categories cannot be null")
509
pandas/_libs/properties.pyx in pandas._libs.properties.CachedProperty.__get__()
~/miniconda3/envs/seaborn-py38-latest/lib/python3.8/site-packages/pandas/core/indexes/base.py in hasnans(self)
2193 """
2194 if self._can_hold_na:
-> 2195 return bool(self._isnan.any())
2196 else:
2197 return False
pandas/_libs/properties.pyx in pandas._libs.properties.CachedProperty.__get__()
~/miniconda3/envs/seaborn-py38-latest/lib/python3.8/site-packages/pandas/core/indexes/base.py in _isnan(self)
2172 """
2173 if self._can_hold_na:
-> 2174 return isna(self)
2175 else:
2176 # shouldn't reach to this condition by checking hasnans beforehand
~/miniconda3/envs/seaborn-py38-latest/lib/python3.8/site-packages/pandas/core/dtypes/missing.py in isna(obj)
125 Name: 1, dtype: bool
126 """
--> 127 return _isna(obj)
128
129
~/miniconda3/envs/seaborn-py38-latest/lib/python3.8/site-packages/pandas/core/dtypes/missing.py in _isna(obj, inf_as_na)
154 # hack (for now) because MI registers as ndarray
155 elif isinstance(obj, ABCMultiIndex):
--> 156 raise NotImplementedError("isna is not defined for MultiIndex")
157 elif isinstance(obj, type):
158 return False
NotImplementedError: isna is not defined for MultiIndex
Expected Output
With an object-typed Series:
import pandas as pd
s = pd.Series(["a", "a", "b"])
s.map({"a": (1, 2), "b": (3, 4)})
0 (1, 2)
1 (1, 2)
2 (3, 4)
dtype: object
Output of pd.show_versions()
INSTALLED VERSIONS
------------------
commit : 2cb96529396d93b46abab7bbc73a208e708c642e
python : 3.8.5.final.0
python-bits : 64
OS : Darwin
OS-release : 19.6.0
Version : Darwin Kernel Version 19.6.0: Mon Apr 12 20:57:45 PDT 2021; root:xnu-6153.141.28.1~1/RELEASE_X86_64
machine : x86_64
processor : i386
byteorder : little
LC_ALL : None
LANG : en_US.UTF-8
LOCALE : en_US.UTF-8
pandas : 1.2.4
numpy : 1.20.2
pytz : 2020.1
dateutil : 2.8.1
pip : 20.3.1
setuptools : 49.6.0.post20210108
Cython : None
pytest : 5.4.3
hypothesis : None
sphinx : 3.3.1
blosc : None
feather : None
xlsxwriter : None
lxml.etree : None
html5lib : None
pymysql : None
psycopg2 : None
jinja2 : 2.11.2
IPython : 7.15.0
pandas_datareader: None
bs4 : None
bottleneck : None
fsspec : None
fastparquet : None
gcsfs : None
matplotlib : 3.4.1
numexpr : None
odfpy : None
openpyxl : None
pandas_gbq : None
pyarrow : None
pyxlsb : None
s3fs : None
scipy : 1.6.3
sqlalchemy : None
tables : None
tabulate : None
xarray : None
xlrd : None
xlwt : None
numba : None
Comment From: ghost
Try this instead:
import pandas as pd
s = pd.Series(["a", "a", "b"]).map({"a": (1, 2), "b": (3, 4)}).astype('category')
````
Output:
0 (1, 2) 1 (1, 2) 2 (3, 4) dtype: category Categories (2, object): [(1, 2), (3, 4)] ```
Comment From: mwaskom
@sanskarbtw thanks but that is not helpful when operating on an input that (may be) categorical