Add new string directories to existing paths in dataset using os.path.join in python

import argparse
import secrets
import string
import random

parser = argparse.ArgumentParser()
parser.add_argument('input', help="inputs")
parser.add_argument("output", help="outputs")
parser.add_argument('search', help="search")
parser.add_argument('--replace', help='replace')
parser.add_argument('percent', help='percent')

args = parser.parse_args()

search_text = args.search
replace_text =  args.replace
replace_text = ''.join(secrets.choice(string.ascii_letters + string.digits)
                                                  for i in range(10))
percent = int(args.percent)

data = open(args.input,'r').read()
nxt = 0
while True:
    nxt = data.find( search_text, nxt )
    if nxt < 0:
        break
    if random.randint(0,100) < percent:
        data = data[:nxt] + replace_text + data[nxt+len(search_text):]
    nxt += len(replace_text)

open(args.output,'w').write(data)
print(replace_text)
print("Text replaced")

I have a dataset containing different paths eg. 'C:\Windows\System32\autofmt.exe' etc. I have written a code to search a word from this path and add a random word in place of it. Now I want to add new directories to that path by taking input from user eg: C:dir1\dir2\dir3\System32\autofmt.exe is there any way I can do that