Replace String with increasing numer [SOLVED]

[bowlofred]

Call it with next as I did in the example above.

next also isn't a callable or a function I can pass around. I'd need to wrap it in something to hand it to re.sub().

If I hand sub a replacement string, then I have to call sub n times for n replacements. But if I hand sub a function, then it goes off and does all the work (in C code) and just calls the function for the replacement when necessary. That second thing is what I was doing for performance. But the argument there must be a true callable that will be handed a match object and must return a string that will become the replacement.

[Yoriz]

from itertools import count
import re

target = "example"
counter = count(1)

paragraph = (
    "This example is an example on how to make an example with the"
    " word example. the example ends here with an example. for example"
)


paragraph = re.sub(re.escape(target), lambda _: f"{next(counter)}", paragraph)

print(paragraph)

Output:
This 1 is an 2 on how to make an 3 with the word 4. the 5 ends here with an 6. for 7

[bowlofred]

Yes, exactly. I was trying for two minutes to wrap it through some method other than a lambda and just gave up. I think I had talked myself into thinking (but not testing) that the lambda wouldn't retain the state and would regenerate the iterator.

[perfringo]

Iteration of ideas already provided (can't be blamed as efficient but easy to write :-):

from itertools import count

paragraph = (
    "This example is an example on how to make an example with the"
    " word example. the example ends here with an example. for example")

counter = count(1)

while 'example' in paragraph:
    paragraph = paragraph.replace('example', f"{next(counter)}", 1)

print(paragraph)

Output:
This 1 is an 2 on how to make an 3 with the word 4. the 5 ends here with an 6. for 7