Custom axis location: is it possible?

Hi guys,
  I need to make a figure with custom axis location. I would like to be able
to put xaxis and yaxis at arbitrary location (instead of the default location
of top, bottom, left, right). One such example would be the symbolline
example at
I could not figure out how to do this with matplotlib after reading the manual
and going through the examples on matplotlib website. I can draw the axis
line myself (with axhline and axvline) but it was very tedious and the result
does not look good. Can this be readily done with matplotlib? Any suggestion
will be appreciated.

Best Wishes,