Replace String in multiple text-files [SOLVED]

[AlphaInc]

As bowlofred already wrote, make a function and then call it for every txt file

import os

folder_path = "/path/to/folder/" # your path
            
for root, dirs, files in os.walk(folder_path, topdown = False):
   for name in files:
      if name.endswith(".txt"):
        file_name = os.path.join(root, name)
        print(file_name)
        #your_function(file_name) # call your function

I tried to do it like this:

#!/usr/bin/env python3

import os
import re

folder_path = "/home/pi/Workspace/Case_02/" # your path

for root, dirs, files in os.walk(folder_path, topdown = False):
   for name in files:
      if name.endswith(".txt"):
        file_name = os.path.join(root, name)

target = "Format"

def str_counter(match_object):
    str_counter.count += 1
    return str(str_counter.count)
str_counter.count = 0

with open(file_name, 'r') as file :
  filedata = file.read()

filedata = re.sub(re.escape(target), str_counter, filedata)

with open(file_name, 'w') as file:
    file.write(filedata)

I set an example with three different files (Out_01.txt, Out_02.txt, Out_03.txt) but the changes to my file were only written to Out_03.txt.

Edit: I just needed to set the right amount of spaces per indentation level.