Is there a way to replace diferent values in a string?

Question

So i'm trying to replace normal numbers for roman numbers, but only the last number is replaced, so i wonder if there's a way to replace diferent values

sample = "Carl 5, 19 century"
numbers = re.findall(r'[0-9]+', sample)
for number in numbers:
    num_int = int(number)
    roman_number = int_to_Roman(num_int)
    new_string = sample.replace(number, roman_number)

>>> Carl 5, XIX century

Here are some other results

sample = "Carl 19, 19 century"
>>> Carl XIX, XIX century

sample = "Carl 5"
>>> Carl V

Answer 1

You can use re.sub() and pass a callable (function) to the repl argument. This callable takes one argument -- the match object, and returns the substitution for that match, so it would likely be a simple wrapper that extracts the match string from the match object and passes it on to int_to_Roman:

def int_to_Roman_wrapper(match_obj):
    return int_to_Roman(int(match_obj.group(0)))


sample = 'Carl 5, 15 century' 
new_string = re.sub(r"\d+", int_to_Roman_wrapper, sample)

Which gives new_string = 'Carl V, XV century'

This doesn't have the problem that the str.replace approach does which tdelaney mentions in their comment:

.replace will replace numbers throughout the string even if they are part of a larger number later on. sample = "Carl 5, 15 century" would fail because the 5 in 15 would be replaced on the first match. The second match would try to replace 15, but its already been destroyed