From Fedora Project Wiki
Draft
This is proposed addendum to Packaging/Python
PyGTK2 and Numpy
If your package uses pygtk2, and calls the gtk.gdk.get_pixels_array() function, that package needs to explicitly Require: numpy. In the past, pygtk2 had a Requires on numpy, but since it is only used for that one function (and that function is not commonly used), the Requires has been removed to minimize the install footprint of pygtk2.
NOTE: This is a temporary workaround which will be resolved in the future. See: INSERT-LINK-TO-PYGTK2-BUG-HERE