How to properly iterate with re.sub() in Python

Question

I want to make a Python script that creates footnotes. The idea is to find all strings of the sort \"Some body text.{^}{Some footnote text.}\" and replace them with

Answer 1

It seems like a good fit for a closure:

def make_footnote_counter(start=1):
    count = [start - 1] # emulate nonlocal keyword
    def footnote_counter(match):
        count[0] += 1
        return "%d" % count[0]
    return footnote_counter

new_body_text = re.sub(pattern, make_footnote_counter(), text)