Installing packages into OSGeo4W64-QGIS-Python and not in Standard Python installation on Windows?

Question

On my Windows 10 PC there are (at least) 2 Python 3.7 versions installed:

a) "Standard Python 3.7 64 bit with IDLE, which I downloaded from the site python.org and installed.

b) The Python 3.7 which comes bundled with the QGIS network-installer OSGeo4W which installed QGIS in the folder c:\OSGeo4W64

Problem:

I need to install some Python-Packages via pip in the Python-version, which is used by QGIS. I dont want to "mess up" my Standard installation of Python.

Answer 1

I think this is more of a Python-specific question than strictly GIS but you should be able to just reference the specific version of Python into which you want to install via an absolute path reference:

See here where the accepted answer shows using an absolute path to a virtual env, just use the path to QGIS's Python executable.