set PYTHONPATH=c:qgispathpython

set PATH=C:qgispath;%PATH%

PYTHONPATH="C:OSGeo4W64appsqgispython"
PATH="C:OSGeo4W64appsqgispythonqgiscore;%PATH%"
import qgis.core

Traceback (most recent call last):
  File "<pyshell#15>", line 1, in <module>
    import qgis.core
ImportError: No module named qgis.core

>>> PYTHONPATH="C:/OSGEO4~1/apps/qgis/./pythonqgis"
>>> import qgis.core

Traceback (most recent call last):
  File "<pyshell#1>", line 1, in <module>
    import qgis.core
ImportError: No module named qgis.core
>>> PATH="C:OSGeo4W64appsqgispythonqgiscore;%PATH%"
>>> import qgis.core

Traceback (most recent call last):
  File "<pyshell#3>", line 1, in <module>
    import qgis.core
ImportError: No module named qgis.core
>>> PATH="C:/OSGEO4~1/apps/qgis/./pythonqgiscore;%PATH%"
>>> import qgis.core

Traceback (most recent call last):
  File "<pyshell#6>", line 1, in <module>
    import qgis.core
ImportError: No module named qgis.core
>>>

set PYTHONPATH=%OSGEO4W_ROOT%\apps\qgis\python
set PATH=%OSGEO4W_ROOT%\apps\qgis\bin;%PATH%