Question

I wrote a script as shown below, I want to replace the strings between StartNum and /StartNum by another variable n. How do I define the position between these two strings in Python?

f1 = open('name.txt', 'r')
f2 = open('result.txt', 'w')
n=5000
for line in f1:
    f2.write(line.replace('(StartNum)(.*)(/StartNum)',str(n)))
    if "StartNum" in line:
        n=n+1

Answer 1

import re
re.sub('(StartNum)(.*)(/StartNum)', r"\1boop\3", 'StartNumbworp/StartNum')

This replaces bworp with boop, so the final string it returns is StartNumboop/StartNum.