I am trying to write two procedures to replace matched strings in a string in python. And I have to write two procedures.

def matched_case(old new): .........

note: inputs are two strings, it returns a replacement converter.

def replacement(x,another_string): ..........

note:inputs are a converter from previous procedure, and a string. It returns the result of applying the converter to the input string.

for example:

a = matched_case('mm','m')
print replacement(a, 'mmmm')
it should return m

another example:

R = matched_case('hih','i')
print replacement(R, 'hhhhhhihhhhh')
it should return hi

I am not sure how can I use loop to do the whole thing. Thanks so much for anyone can give a hint.

def subrec(pattern, repl, string):while pattern in string:string = string.replace(pattern, repl)return string

foo('mm', 'm', 'mmmm') return m

foo('hih', 'i', 'hhhhhhihhhhh') return hi