正则替換

特殊字符：\.^$?+*{}[]()|

re.search  全文一次搜索到停止
re.match   全文開頭一次搜索停止

def sub_once_a_time(pattern, raw_str):
    before_str = "0"
    after_str = raw_str
    sub_list = []
    count_sub = 1
    while after_str != before_str:
        before_str = after_str
        repl_str = "sub_" + str(count_sub)
        value = re.search(pattern, before_str)
        after_str = re.sub(pattern, repl_str, before_str, count=1)
        sub_list.append({repl_str: value})
        count_sub += 1
    return sub_list