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

A variation and Python-3-only solution:

def make_create_footnote_numbers(start=1):
    count = start - 1
    def create_footnote_numbers(match):
        nonlocal count
        count += 1
        return "{}".format(count)
    return create_footnote_numbers

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