find some text words in files and replace it to other words

data-find-and-replace.py

#!/usr/bin/env python3
# -*- mode: python; coding: utf-8 -*-

assert str is not bytes

import sys
import os, os.path
import csv
import itertools
import random

def replace_middle_iter_create():
    for i in itertools.count():
        rnd_str = '*'.join(str(random.randrange(10)) for r_i in range(10))
        replace_middle = '**{}*{}**'.format(rnd_str, i)
        
        yield replace_middle

def out_name_iter_create():
    for i in itertools.count():
        out_name = 'out-{}.txt'.format(i)
        
        yield out_name

def main():
    if len(sys.argv) != 4:
        exit(code=2)
    
    source_dir = sys.argv[1]
    replace_csv_path = sys.argv[2]
    out_dir = sys.argv[3]
    
    source_path_list = []
    replace_list = []
    replace_middle_iter = replace_middle_iter_create()
    
    out_name_iter = out_name_iter_create()
    
    for r, d, f in os.walk(source_dir):
        for source_name in f:
            if not source_name.endswith('.txt'):
                continue
            
            source_path = os.path.join(r, source_name)
            
            source_path_list.append(source_path)
    
    with open(replace_csv_path, encoding='utf-8', errors='replace') as replace_csv_fd:
        replace_csv = csv.reader(replace_csv_fd)
        for replace_row in replace_csv:
            if len(replace_row) != 2:
                continue
            
            replace_source = replace_row[0]
            replace_middle = next(replace_middle_iter)
            replace_target = replace_row[1]
            
            replace_list.append((
                replace_source,
                replace_middle,
                replace_target,
            ))
    
    os.mkdir(out_dir)
    
    for source_path in source_path_list:
        with open(source_path, encoding='utf-8', errors='replace') as source_fd:
            orig_data = source_fd.read()
            data = orig_data
            
            for replace_source, replace_middle, replace_target in replace_list:
                if replace_source not in data:
                    continue
                
                data = data.replace(replace_source, replace_middle, 1)
            
            for replace_source, replace_middle, replace_target in replace_list:
                if replace_middle not in data:
                    continue
                
                data = data.replace(replace_middle, replace_target)
            
            if orig_data != data:
                out_path = os.path.join(out_dir, next(out_name_iter))
                
                with open(out_path, mode='w', encoding='utf-8', newline='\n') as out_fd:
                    out_fd.write('{}\n'.format(data))

if __name__ == '__main__':
    main()