How do I add tab completion to the Python shell?

Python 2.5.1 (r251:54863, Apr 15 2008, 22:57:26)
[GCC 4.0.1 (Apple Inc. build 5465)] on darwin
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(InteractiveConsole)

# ~/.pythonrc
# enable syntax completion
try:
    import readline
except ImportError:
    print "Module readline not available."
else:
    import rlcompleter
    readline.parse_and_bind("tab: complete")

export PYTHONSTARTUP=~/.pythonrc