pygtk

Although I have python-gtk installed I still get this error message when
importing pylab. I'm not sure why. Can anyone enlighten me?

from pylab import *

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib64/python2.6/site-packages/pylab.py", line 1, in <module>
    from matplotlib.pylab import *
  File "/usr/lib64/python2.6/site-packages/matplotlib/pylab.py", line
253, in <module>
    from matplotlib.pyplot import *
  File "/usr/lib64/python2.6/site-packages/matplotlib/pyplot.py", line
75, in <module>
    new_figure_manager, draw_if_interactive, show = pylab_setup()
  File
"/usr/lib64/python2.6/site-packages/matplotlib/backends/__init__.py",
line 25, in pylab_setup
    globals(),locals(),[backend_name])
  File
"/usr/lib64/python2.6/site-packages/matplotlib/backends/backend_gtkagg.py",
line 10, in <module>
    from matplotlib.backends.backend_gtk import gtk, FigureManagerGTK,
FigureCanvasGTK,\
  File
"/usr/lib64/python2.6/site-packages/matplotlib/backends/backend_gtk.py",
line 11, in <module>
    raise ImportError("Gtk* backend requires pygtk to be installed.")
ImportError: Gtk* backend requires pygtk to be installed.