if $CONDITION == "some_value":
    from Dir1.MyModule import *
else:
    from Dir2.MyModule import *

import commands
if commands.getoutput('echo $CONDITION') == "some_value":
    from Dir1.MyModule import *
else:
    from Dir2.MyModule import *

import os
if os.environ["CONDITION"]:

>>> commands.getoutput("echo PYTHONPATH")
"'{' is not recognized as an internal or external command,\noperable program or batch file."