Glade is linked to the system libs for its embedded python :
Keiths-MBP:MacOS keith$ otool -L glade
/System/Library/Frameworks/Python.framework/Versions/2.7/Python (compatibility version 2.7.0, current version 2.7.10)
I believe you can control the framework search path using the env var DYLD_FRAMEWORK_PATH if you want it to pick up a non-standard python framework?
Then the module load path (sys.path) is set using the env var PYTHONPATH.