Replace part of a string in python multiple times but each replace increments a number in the string by 1

Question

I am modifying html tags in a large html file by giving each tag a unique name with different numbers. So that a javascript function can reference those tags with the modified n

Answer 1

If you use re.sub() to do the replacing, you can pass a function as the second argument rather than a plain string. The function will receive a match object based on what the regex matched. You can then use some thinking like itertools.count() (or your own object) to produce increasing numbers.

For example:

import re
from itertools import count

button_number_count = 1;
htmlString = "this is sometext with more sometext and yet another sometext"

counter = count(button_number_count)

// replace sometext with sometext1, sometext2...
new_string = re.sub(r'sometext', lambda x: x.group(0) + str(next(counter)), htmlString )

The new_string will look like:

'this is sometext1 with more sometext2 and yet another sometext3'