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

Any callable can be used, so you could use a class to track the numbering:

class FootnoteNumbers(object):
    def __init__(self, start=1):
        self.count = start - 1

    def __call__(self, match):
        self.count += 1
        return "{}".format(self.count)


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

Now the counter state is contained in the FootnoteNumbers() instance, and self.count will be set anew each time you start a re.sub() run.