[Python] Search and replace one by one in python

I try to find patterns in a Markdown expression. This is my code:

import re

redmineToGitlabIdMap = dict()
redmineToGitlabIdMap[150767] = { 'iid': 1 }
redmineToGitlabIdMap[150768] = { 'iid': 2 }
redmineToGitlabIdMap[150769] = { 'iid': 3 }

description = '*(from redmine: issue id 150767, created on 2024-02-27 by **me**)*\n\n* Relations:\n * copied_to #150767\n * relates #150768\n * relates #150769'
pattern = r'(\s*\* (?:relates|parent|child|copied_to)) #(\d+)'

for _, redmineId in re.findall(pattern, description):
targetGitlabId = redmineToGitlabIdMap[int(redmineId)]['iid']
description = re.sub(pattern, f'\\1 #{ targetGitlabId }', description, count=1)

print(description)



As you can see I'm iterating the matches found by the regular expression, in order to replace them one by one by their respective values from the redmineToGitlabIdMap dictionary.

However when I execute that, it will always only replace the very first occurrence and return this

* Relations:
* copied_to #3
* relates #150768
* relates #150769


while this should be printed instead:

* Relations:
* copied_to #1
* relates #2
* relates #3

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