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          


        

Answer 1

you may reverse a string like so:

myStr[::-1]

to replace just add the .replace:

print myStr[::-1].replace("iss","XXX",1)

however now your string is backwards, so re-reverse it:

myStr[::-1].replace("iss","XXX",1)[::-1]

and you're done. If your replace strings are static just reverse them in file to reduce overhead. If not, the same trick will work.

myStr[::-1].replace("iss"[::-1],"XXX"[::-1],1)[::-1]