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

def rreplace(s, old, new):
    try:
        place = s.rindex(old)
        return ''.join((s[:place],new,s[place+len(old):]))
    except ValueError:
        return s