Becoming root within a Python script

[François Pinard]

Hi, people.  I have a small problem, for which I see no elegant solution yet.
Is there a common idiom I could use?

I would like, within a executing Python started as non-root, ask for the root
password, and then, continue executing part of the script while being root,
becoming the previous again after some sub-job is done.

Of course, I can kludge something in, but I would prefer something nice. :-)

-- 
François Pinard   http://www.iro.umontreal.ca/~pinard