#!/bin/bash
 
# ideone boilerplate - we can't write files in the home directory;
# so create a temporary directory for our files instead
t=$(mktemp -d -t ideone.XXXXXXXXXXXX) || exit
trap 'rm -rf "$t"' ERR EXIT
cd "$t"
 
cat <<\: >password.txt
 DBFS_USR  ABCDEF   # assume you want DBFS_USR, not DB_USR
 DB_MGR    QWERTY
:
 
cat <<\: >prog.py
# import sys  # remove unused import
# import logging  # remove unused import
import re
 
def file_to_array(file_info):
    with open (file_info,'rt') as fh:  # typo fixed
        pw_lines = [x.strip() for x in fh.readlines() if not x.startswith('#')] #ignore comments
    return pw_lines
 
for line in [re.sub(r'^(\s*DBFS_USR\s+)\S+', r'\1PQRSTU', line) for line in file_to_array("password.txt")]:
    print(line)
:
 
python3 prog.py

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