I had 2 installations of QGIS. One was through OSGeo4W, while the other one was installed independently.

I too faced the same qgis import error issue. This is what I did.

Just TWO changes:

1. PYTHONPATH = C:\OSGeo4W\apps\qgis\python; C:\OSGeo4W\apps\qgis\python\plugins; C:\OSGeo4W\apps\Python39\Lib\site-packages

2. Path(in system variables): C:\OSGeo4W\apps\qgis\python (Add this path and "move down" any other existing path to QGIS)

Also, make sure that the paths that you require are moved to the top of Path variable list.

I had 2 installations of QGIS. One was through OSGeo4W, while the other one was installed independently.

I too faced the same qgis import error issue. This is what I did.

Just TWO changes:

1. PYTHONPATH = C:\OSGeo4W\apps\qgis\python; C:\OSGeo4W\apps\qgis\python\plugins; C:\OSGeo4W\apps\Python39\Lib\site-packages; C:\OSGeo4W\apps\qgis\python\qgis;

2. Path(in system variables): C:\OSGeo4W\apps\qgis\python C:\OSGeo4W\apps\qgis\python\qgis (Add this path and "move down" any other existing path to QGIS)

Also, make sure that the paths that you require are moved to the top of Path variable list.