ImportError: DLL load failed with Windows wheel for 1.0.2 and 1.0.3

[J-Postma]

When trying to install pandas 1.0.2 or newer versions on a docker, I run into the following import error:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Python\lib\site-packages\pandas\__init__.py", line 55, in <module>
    from pandas.core.api import (
  File "C:\Python\lib\site-packages\pandas\core\api.py", line 29, in <module>
    from pandas.core.groupby import Grouper, NamedAgg
  File "C:\Python\lib\site-packages\pandas\core\groupby\__init__.py", line 1, in <module>
    from pandas.core.groupby.generic import DataFrameGroupBy, NamedAgg, SeriesGroupBy
  File "C:\Python\lib\site-packages\pandas\core\groupby\generic.py", line 60, in <module>
    from pandas.core.frame import DataFrame
  File "C:\Python\lib\site-packages\pandas\core\frame.py", line 124, in <module>
    from pandas.core.series import Series
  File "C:\Python\lib\site-packages\pandas\core\series.py", line 4572, in <module>
    Series._add_series_or_dataframe_operations()
  File "C:\Python\lib\site-packages\pandas\core\generic.py", line 10349, in _add_series_or_dataframe_operations
    from pandas.core.window import EWM, Expanding, Rolling, Window
  File "C:\Python\lib\site-packages\pandas\core\window\__init__.py", line 1, in <module>
    from pandas.core.window.ewm import EWM  # noqa:F401
  File "C:\Python\lib\site-packages\pandas\core\window\ewm.py", line 5, in <module>
    import pandas._libs.window.aggregations as window_aggregations
ImportError: DLL load failed while importing aggregations: The specified module could not be found.

I've reproduced this error on a separate pc by running:

docker run -it python cmd.exe
pip install pandas
python
import pandas

This error only occurs when trying to import pandas from the docker. Python and pip versions:

python 3.8.2
pip 20.0.2

[TomAugspurger]

Things work for you with pandas 1.0.1 and earlier?

[J-Postma]

Yes, things were fine with pandas 1.0.1 or any of the 0.* versions

[TomAugspurger]

Thanks. We switched our wheel building infrastructure for 1.0.3, but if it's happening on 1.0.2 as well that's likely not it.

I'm not aware of anyone else using pandas inside a windows docker container. You might be on your own here, so anything you can do to debug this would be welcome.

[TomAugspurger]

Can you create a new environment and post the full output of this?

pip install pandas
python -c "import pandas"

For both pandas 1.0.2 and 1.0.3 potentially.

[AaryamanCodes]

So, I too faced the exact error. I tried it on Jupyter notebooks and it worked though I could still not import some other pandas submodules.

[TomAugspurger]

From @mborus:

TLDR; 2 DLLs are missing that were included in 1.0.1

Code Sample, a copy-pastable example if possible

import pandas as pd

Problem description

I'm using Windows 7, German 64bit with a fresh installation of Python 3.8.2 64bit.
I updated pip, created a fresh virtual environment with "py -3 -m venv venv" and activated it.
This installation is in a restricted area with no direct, unfiltered internet access.

I installed Pandas 1.0.3 from a via "python -m pip download pandas" download made on an unrestricted similar Windows7 machine. I moved the download folder behind a firewall and installed Pandas like this: "python -m pip install pandas --no-index --find-links /path/to/downloads":

Pandas installs fine. It crashes on import with the error below (The last sentence says in English: The requested Module was not found)

As recommended by this stack overflow thread (https://stackoverflow.com/questions/60763529/unable-to-import-pandas-pandas-libs-window-aggregations) going back to 1.0.1 fixes the problem. (More below, after the error)

Error:

(venv) C:\my_program>python
Python 3.8.2 (tags/v3.8.2:7b3ab59, Feb 25 2020, 23:03:10) [MSC v.1916 64 bit (AM
D64)] on win32
Type "help", "copyright", "credits" or "license" for more information.

import pandas as pd
Traceback (most recent call last):
File "", line 1, in
File "C:\my_program\venv\lib\site-packages\pandas_init_.py", line 5
5, in
from pandas.core.api import (
File "C:\my_program\venv\lib\site-packages\pandas\core\api.py", line 2
9, in
from pandas.core.groupby import Grouper, NamedAgg
File "C:\my_program\venv\lib\site-packages\pandas\core\groupby_init
_.py", line 1, in
from pandas.core.groupby.generic import DataFrameGroupBy, NamedAgg, SeriesGr
oupBy
File "C:\my_program\venv\lib\site-packages\pandas\core\groupby\generic
.py", line 60, in
from pandas.core.frame import DataFrame
File "C:\my_program\venv\lib\site-packages\pandas\core\frame.py", line
124, in
from pandas.core.series import Series
File "C:\my_program\venv\lib\site-packages\pandas\core\series.py", lin
e 4572, in
Series._add_series_or_dataframe_operations()
File "C:\my_program\venv\lib\site-packages\pandas\core\generic.py", li
ne 10349, in add_series_or_dataframe_operations
from pandas.core.window import EWM, Expanding, Rolling, Window
File "C:\my_program\venv\lib\site-packages\pandas\core\window_init
.py", line 1, in
from pandas.core.window.ewm import EWM # noqa:F401
File "C:\my_program\venv\lib\site-packages\pandas\core\window\ewm.py",
line 5, in
import pandas._libs.window.aggregations as window_aggregations
ImportError: DLL load failed while importing aggregations: Das angegebene Modul
wurde nicht gefunden.

I compared the installation of version 1.0.1 to 1.0.3;

The 1.0.3 installs these files in
"\venv\Lib\site-packages\pandas_libs\window"

    __init__.py
    aggregations.cp38-win_amd64.pyd
    indexers.cp38-win_amd64.pyd

The 1.0.1 version also installs these two DLLs in the same folder.

    concrt140.dll
    msvcp140.dll

When I manually place these DLLs into the above folder of the 1.0.3 version,
the import works without an error.

Expected Output

No error message

Output of pd.show_versions()

Not available, since pd did not import

[TomAugspurger]

To everyone in this issue, does the problem occur using wheels from pandas 1.0.2 and 1.0.3?

[mborus]

Can't say for 1.0.2, but I have installed the 1.0.3 wheel "pandas-1.0.3-cp38-cp38-win_amd64.whl" and extracted the DLLs from "pandas-1.0.1-cp38-cp38-win_amd64.whl"

[TomAugspurger]

@mborus can you try for 1.0.2? Our wheel building infrastructure changed for 1.0.3, but we've had users report issues with 1.0.2 as well.

[mborus]

I'll give it a try. This may take a while because the process of getting the Pandas wheel behind the firewall is a bit complicated. I'll post the result when I know more.

[TomAugspurger]

Thanks!