Python。代码重复多次，因为执行它的命令不同

Question

我已经使用 Python 修补了一个 Discord 机器人，它已经可以正常工作了，但是有一个问题。

这段代码会重复多次，每个帖子类别一次，现在我有随机、有趣、体育、游戏和新闻，所以你可以看到它的冗余以及它会进一步变成什么，如果需要的话制作更多类别。

if '!random' in messageContent:
                channel = int(chanRandom.strip('"'))
                channel = client.get_channel(channel)
                while c < 50:
                    if messageContent == '!random':
                        submission = next(x for x in randomList[sortListHot] if not x.stickied)
                        sortType   = 'Hot sorting'
                    elif messageContent == '!random top':
                        submission = next(x for x in randomList[sortListTop] if not x.stickied)
                        sortType   = 'Top sorting'
                    elif messageContent == '!random new':
                        submission = next(x for x in randomList[sortListNew] if not x.stickied)
                        sortType   = 'New sorting'
                    with open(urlFile, 'r') as urlRead:
                        if str(submission.url) not in urlRead.read():
                            await channel.send(f"{submission.url}\n{submission.title}\n<https://reddit.com{submission.permalink}>")
                            await channel.send("-------------------------")
                            with open(urlFile, 'a+') as urlWrite:
                                urlWrite.write(str(f'{submission.url}\n'))
                            c += 2
                        else:
                            print(f'{messageContent} repost: {submission.url}')
                await channel.send(sortType)

我现在的想法是创建一个包含所有可能命令的列表，但问题是使用变量 channel = int(chanRandom.strip('"')) 在正确的频道中发布，该变量会根据使用的命令 channel = int(chanNews.strip('"')) 等发生变化。

内存使用也存在问题，因为我认为机器人正在保存所有内容，但没有必要，但这是另一个问题。

感谢任何帮助。

Answer 1

我在这里看不到所有变量的内容，但如果你想减少代码重复，我建议制作一个字典并将不同的变量映射到用户输入。

这是它的想法：

my_mapping = {
    "!random": (sortListHot, "Hot sorting"),
    "!random top": (sortListTop, "Top sorting"),
    "!random new": (sortListNew, "New sorting")
}

sorting_type = my_mapping[messageContent.lower()][0]  # sortListHot/Top/New
sorting_text = my_mapping[messageContent.lower()][1]  # "Hot/Top/New sorting"

submission = next(x for x in randomList[sortingType] if not x.stickied)

将这些映射到字典还可以轻松灵活地添加更多条目（只需添加一个新键，其值是遵循当前模式的元组）。

添加.lower() 是为了不区分大小写。

我还可以建议查看命令装饰器，而不是使用 on_message 事件。

---

参考资料：

• Dictionaries in Python
• str.lower()
• commands.Command() - 强烈建议切换到此。

Answer 2

感谢@Diggy。我能够完成代码。这是新版本：

messageContentTop = str.replace(messageContent, ' top','')
            messageContentNew = str.replace(messageContent, ' new', '')

            if messageContent or messageContentTop or messageContentNew in multiCom:
                if 'top' in messageContent:
                    channel = int(multiCom[messageContentTop][3])
                elif 'new' in messageContent:
                    channel = int(multiCom[messageContentNew][3])
                else:
                    channel = int(multiCom[messageContent][3])

                channel = client.get_channel(channel)
                while c < 50:
                    if 'new' and 'top' not in messageContent:
                        submission = next(x for x in multiCom[messageContent][4] if not x.stickied)
                        sortType   = 'Hot sorting'
                    elif 'top' in messageContent:
                        submission = next(x for x in multiCom[messageContentTop][5] if not x.stickied)
                        sortType   = 'Top sorting'
                    elif 'new' in messageContent:
                        submission = next(x for x in multiCom[messageContentNew][6] if not x.stickied)
                        sortType   = 'New sorting'
                    with open(urlFile, 'r') as urlRead:
                        if str(submission.url) not in urlRead.read():
                            await channel.send(f"{submission.url}\n{submission.title}\n<https://reddit.com{submission.permalink}>")
                            await channel.send("-------------------------")
                            with open(urlFile, 'a+') as urlWrite:
                                urlWrite.write(str(f'{submission.url}\n'))
                            c += 2
                        else:
                            print(f'{messageContent} repost: {submission.url}')
                await channel.send(sortType)

multiCom（多个命令，我会想一个更好的名字）字典是这样设置的：

multiCom = {
    '!random':  ('!random',  '!random top',  'random new',   randomChan,  reddit.subreddit(randomSubs).hot(),  reddit.subreddit(randomSubs).top(),  reddit.subreddit(randomSubs).new()),
    '!funny':   ('!funny',   '!funny top',   '!funny new',   funnyChan,   reddit.subreddit(funnySubs).hot(),   reddit.subreddit(funnySubs).top(),   reddit.subreddit(funnySubs).new()),
    '!news':    ('!news',    '!news top',    '!news new',    newsChan,    reddit.subreddit(newsSubs).hot(),    reddit.subreddit(newsSubs).top(),    reddit.subreddit(newsSubs).new())
}

randomChan、funnyChan、newsChan 是存储服务器频道 ID 的变量。

从旧版本中清理了大约 20kb，速度明显更快！

Answer 3

如果您的代码不符合简单模式并且想要使用类似于 switch/case 语句的结构，您可以编写一个辅助函数来模拟它：

 def switch(value): yield lambda *match: value in match

使用示例：

 for case in switch(messageContent):

     if   case('!random'):
          submission = next(x for x in randomList[sortListHot] if not x.stickied)
          sortType   = 'Hot sorting'

     elif case('!random top'):
          submission = next(x for x in randomList[sortListTop] if not x.stickied)
          sortType   = 'Top sorting'

     elif case('!random new'):
          submission = next(x for x in randomList[sortListNew] if not x.stickied)
          sortType   = 'New sorting'