Right-to-left string replace in Python?

Question

I want to do a string replace in Python, but only do the first instance going from right to left. In an ideal world I'd have:

myStr = "mississippi"
print myStr.rreplace("iss","XXX",1)

> missXXXippi

What's the best way of doing this, given that rreplace doesn't exist?

Answer 1

rsplit and join could be used to simulate the effects of an rreplace

>>> 'XXX'.join('mississippi'.rsplit('iss', 1))
'missXXXippi'