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Description
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I have confirmed this bug exists on the latest version of pandas.
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(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
df = pd.DataFrame(
{'kind' : ['a', 'b', 'a'],
'value' : [1, 2, 3]})
res: pd.Series = df['kind'] == 'a'
print(type(res))Problem description
mypy returns the following error:
$ mypy test.py
test.py:7: error: Incompatible types in assignment (expression has type "bool", variable has type
"Series")
res: pd.Series = df['kind'] == 'a'
^
Found 1 error in 1 file (checked 1 source file)
$ mypy --version
mypy 0.812
But actual type of the result at runtime is Series:
$ python test.py
<class 'pandas.core.series.Series'>
Expected Output
No compile errors.
Output of pd.show_versions()
>>> pd.show_versions()
INSTALLED VERSIONS
------------------
commit : f2c8480af2f25efdbd803218b9d87980f416563e
python : 3.8.5.final.0
python-bits : 64
OS : Linux
OS-release : 5.4.0-70-generic
Version : #78-Ubuntu SMP Fri Mar 19 13:29:52 UTC 2021
machine : x86_64
processor : x86_64
byteorder : little
LC_ALL : None
LANG : en_US.UTF-8
LOCALE : en_US.UTF-8
pandas : 1.2.3
numpy : 1.20.2
pytz : 2021.1
dateutil : 2.8.1
pip : 20.0.2
setuptools : 44.0.0
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
fsspec : None
fastparquet : None
gcsfs : None
matplotlib : None
numexpr : None
odfpy : None
openpyxl : None
pandas_gbq : None
pyarrow : None
pyxlsb : None
s3fs : None
scipy : None
sqlalchemy : None
tables : None
tabulate : None
xarray : None
xlrd : None
xlwt : None
numba : None
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Arithmetic, Comparison, and Logical operationsArithmetic, Comparison, and Logical operationstype annotations, mypy/pyright type checkingtype annotations, mypy/pyright type checking