Using PyQGIS functions outside QGIS

Question

I want to use PyQGIS function crs.isValid() in normal Python file outside of QGIS like this:

wkt = 'GEOGCS["WGS84", DATUM["WGS84", SPHEROID["WGS84", 6378137.0, 298.257223563]],' \
      'PRIMEM["Greenwich", 0.0], UNIT["degree",0.017453292519943295],' \
      'AXIS["Longitude",EAST], AXIS["Latitude",NORTH]]'
crs = QgsCoordinateReferenceSystem(wkt)
assert crs.isValid()

In the documentation it says that:

If you’re outside the PyQGIS console, the code snippets on this page need the following imports:

from qgis.core import (QgsCoordinateReferenceSystem,
                       QgsCoordinateTransform,
                       QgsProject,
                       QgsPointXY
                       )

But it doesn't mention how to install qgis.core to my Python. If I do something like pip install qgis I get this error message:

ERROR: Could not find a version that satisfies the requirement qgis (from versions: none) ERROR: No matching distribution found for qgis

Is there a way to use PyQGIS functions in a standalone Python file?