obama

#!/usr/bin/python3
# -*- coding: UTF-8 -*-

import sys
import re
from os import listdir

def arg_parse():
    global source_pattern
    global repl_pattern
    global path

    if len(sys.argv)>=3:
        path = str(sys.argv[1])
        if not path.endswith('/'): #дополняем путь закрывающим слэшем,
            path += '/'           #если он отсутствует
        source_pattern = str(sys.argv[2])
        if len(sys.argv)>3:
            repl_pattern = str(sys.argv[3])
        else:
            repl_pattern = ''
    else:
        error()
def error():
    print('Usage: python3 obama.py PATH SOURCE_PATTERN REPLACE_PATTERN')
    exit()


def prompt(path, source_pattern, repl_pattern):
    if repl_pattern == '':
        zam = 'EMPTY PATTERN, just delete source text'
    else:
        zam = repl_pattern
    submit = input('Are you sure you want to replace "' + source_pattern +'"  for "' + zam + '" in all files of ' + path + ' ?')
    if submit == 'Y' or submit == 'y':
        replace(path, source_pattern, repl_pattern)

def replace(path, source_pattern, repl_pattern):
    for f in listdir(path):
        fh = file(f, 'r')
        output = re.sub(source_pattern, repl_pattern, fh.read())
        fh.close()

        f_out = file(f, 'w')
        f_out.write(output)
        print(path + f + ' is changed and saved')
        f_out.close()


if __name__ == "__main__":
    arg_parse()
    prompt(path, source_pattern, repl_pattern)
    replace(path, source_pattern, repl_pattern)