How to replace all occurences except the first one?

Question

How to replace all the repeated words except the first one in the string? That is these strings

s=\'cat WORD dog WORD mouse WORD\'
s1=\'cat1 WORD dog1 WORD\'         


        

Answer 1

Use a string.count together with the rreplace

>>> def rreplace(s, old, new, occurrence):
...     li = s.rsplit(old, occurrence)
...     return new.join(li)
... 
>>> a
'cat word dog word mouse word'
>>> rreplace(a, 'word', 'xxx', a.count('word') - 1)
'cat word dog xxx mouse xxx'