I have some directories in PATH that contain different versions of GDAL (I know removing them from PATH would fix this issue). Looking into osgeo/init.py I can see that these directories are added ...
Setting the env variable USE_PATH_FOR_GDAL_PYTHON=YES causes from osgeo import gdal to fail with a different error: Traceback (most recent call last): File "demo.py", line 1, in <module> from osgeo ...