如何从字符串中提取日期？

Question

例如，我正在创建一个类似Reddit的RemindMeBot的Twitter机器人（如果有人熟悉的话）。如果用户在推文中提及该机器人，则希望在30秒内用“！在30秒内记住”一句来提醒他们，我将如何在该时间范围内提醒他们？

这几乎是我想要获得的以下功能：

def reply_to_tweets():
    """Replies to users who mention the user with date requested"""
        print('Searching through mentions...')
        last_seen_id = retrieve_last_seen_id(name_of_file)
        # Extended tweet mode is for showing longer tweets in mentions
        mentions = api.mentions_timeline(last_seen_id, tweet_mode='extended')
        target_date = datetime.datetime.strptime('%d/%m/%y %H:%M')
        for mention in reversed(mentions):
            if target_date in mention.full_text:
                print('Found tweet!' + ' MENTION ID: ' + str(mention.id))
                print('Replying back to tweet...')
                if target_date:
                    api.update_status("@{} Here's your reminder.".format(mention.user.screen_name))
                    last_seen_id = mention.id
                    store_last_seen_id(last_seen_id, name_of_file)