I'm trying to perform a number of replacements using re.sub(), except I want the first replacement to be different. One straightforward approach would be to run re.sub() twice with count = 1 for the first call, but because re.sub() allows for the repl argument to be a function, we can do this in a single call:
import re
def repl(matchobj):
global first_sub
if first_sub:
first_sub = False
print(f"Replacing '{matchobj.group()}' at {matchobj.start()} with ':)'")
return ":)"
else:
print(f"Deleting '{matchobj.group()}' at {matchobj.start()}")
return ""
text = "hello123 world456"
first_sub = True
text = re.sub(r"\d+", repl, text)
# Output:
# Replacing '123' at 5 with ':)'
# Deleting '456' at 14
Unfortunately, this makes use of global, which isn't great. Is there a better way to do this?
