ImportError DLL load fails for importing cartopy.crs

[CHC278Cao]

Description

Hello! I get a ImportError for importing Cartopy in python 3.7. I installed the Cartopy 0.20 and all dependency with wheel file, and I tried to reinstall the Cartopy, the ImportError is still here.

Code to reproduce

import cartopy.crs as ccrs

Traceback

Traceback (most recent call last):
  File "F:/workspace/maps/src/test.py", line 11, in <module>
    import cartopy.crs as ccrs
  File "F:\workspace\maps\env\lib\site-packages\cartopy\__init__.py", line 110, in <module>
    import cartopy.crs
  File "F:\workspace\maps\env\lib\site-packages\cartopy\crs.py", line 27, in <module>
    import cartopy.trace
ImportError: DLL load failed: The specified module could not be found.

Full environment definition

I download the Cartopy and its dependency from https://www.lfd.uci.edu/~gohlke/pythonlibs/, and the files I get as follows:
- Cartopy-0.20.2-cp37-cp37m-win_amd64.whl - GDAL-3.4.2-cp37-cp37m-win_amd64.whl - matplotlib-3.5.1-cp37-cp37m-win_amd64.whl - numpy-1.21.5+mkl-cp37-cp37m-win_amd64.whl - Pillow-8.4.0-cp37-cp37m-win_amd64.whl - pyproj-3.2.1-cp37-cp37m-win_amd64.whl - pyshp-2.2.0-py3-none-any.whl - Shapely-1.8.1.post1-cp37-cp37m-win_amd64.whl

Operating system

Windows 10 64 bit, Python 3.7.9

Cartopy version

Cartopy - 0.20.2

conda list

pip list

Cartopy==0.20.2
GDAL==3.4.2
matplotlib==3.5.1
Pillow==8.4.0
pyproj==3.2.1
pyshp==2.2.0
Shapely==1.8.1.post1
six==1.16.0

[dopplershift]

Try to reinstall shapely from source instead of the wheel file: pip install --no-binary shapely.

[freol35241]

Hi, I have been running in to this problem lately as well and it seems related to the shapely version?

with:

Shapely==1.8.1.post1  --> DLL import error
Shapely==1.8.1        --> DLL import error
Shapely==1.8.0        --> OK

So, as a workaround for now, pin your shapely version to 1.8.0.

[firobeid]

Hell @dopplershift! Is there a py3-none-any.whl wheel for installing cartopy or a wasm version wheel?

[dopplershift]

@firobeid Currently Cartopy doesn't release wheels (#1174) due to challenges maintaining build compatibility with Shapely. Even if we did, they wouldn't be py3-none-any due to the fact that Cartopy currently needs to build some compiled extension modules (#2080 might help here).

For Wasm, building in Pyodide has been on my list, but I haven't gotten around to it.

[greglucas]

We have just released v0.22 which should help with the compatibility between packages and installation much easier. Please open a new issue if you are still having problems.