Import Errors: fiona and gdal

Question

I can neither import fiona nor gdal.

I installed the following Python version:

Python 3.9.4 (tags/v3.9.4:1f2e308, Apr  6 2021, 13:40:21) [MSC v.1928 64 bit (AMD64)]

Furthermore I installed the following :numpy, shapely, gdal, and fiona and am using Spyder for coding. Also I installed Visual Studio to be able to run C++.

I used pip to install numpy and shapely. For gdal I downloaded GDAL 3.4.1, released 2021/12/27 from: https://www.gisinternals.com/archive.php

I have added some environmental variables to windows for gdal, not sure if they are correct. While trying to solve the import problem I added more and more at different places...

I have installed Fiona 1.8.21 with the Fiona-1.8.21-cp39-cp39-win_amd64.whl from here using pip install.

So now my problem.

When I try to first import fiona, then that's the output:

import fiona
Traceback (most recent call last):

  File "C:\Users\AN\AppData\Local\Temp\ipykernel_4032\1102285635.py", line 1, in <cell line: 1>
    import fiona

  File "c:\users\an\appdata\local\programs\python\python39\lib\site-packages\fiona\__init__.py", line 89, in <module>
    from fiona.collection import BytesCollection, Collection

  File "c:\users\an\appdata\local\programs\python\python39\lib\site-packages\fiona\collection.py", line 11, in <module>
    from fiona.ogrext import Iterator, ItemsIterator, KeysIterator

ImportError: DLL load failed while importing ogrext: The specified module could not be found.

When I first try to import gdal, error no module named gdal occurs. When I then try to import fiona the following errors occur:

import gdal

  File "C:\Users\AN\AppData\Local\Temp\ipykernel_4032\3648793768.py", line 1, in <cell line: 1>
    import gdal

ModuleNotFoundError: No module named 'gdal'

import fiona

  File "c:\users\an\appdata\local\programs\python\python39\lib\site-packages\fiona\__init__.py", line 88, in <module>
    with fiona._loading.add_gdal_dll_directories():

AttributeError: partially initialized module 'fiona' has no attribute '_loading' (most likely due to a circular import)

How can I fix this?