Virtualenv: TclError Cannot find useful init.tcl

Question

issue: running Python matplotibfrom a virtual Windows environment, as reported and discussed by Github ticket 93 , and the corresponding proposed fix here .

Code ( myp.py):

     import matplotlib.pyplot as pl
     import Tkinter as tk
     # insert code to read/load mydata
     pl.plot(mydata['foo'],mydata['bar'],'*')

Tcl error:

 _tkinter.TclError: Can't find a usable init.tcl in the following directories: 
C:/Python27/lib/tcl8.5 C:/Users/Remi/MyVirtEnv/lib/tcl8.5....(ect)

Fix attempt 1: as suggested in the ticket above, I added the following env. variables to the path in the batch file activate.batlocated in C:/Users/Remi/MyVirtEnv/Scripts/:

set "TCL_LIBRARY=C:\Python27\tcl\tcl8.5"
set "TK_LIBRARY=C:\Python27\tcl\tk8.5"

Not allowed this way. Potentially relevant information: using an PyCharmIDE with the following configuration:

Environment variables: PYTHONUNBUFFERED=1
Python interpreter: python 2.7.10 virtualenv at C:\Users\Remi\MyVirtEnv
"buttons checked": Add content roots and Add source roots to PYTHONPATH

Any help I could get would be greatly appreciated.