如何实现按字符串中的数值降序排列列表元素并应用于Discord LastFM机器人命令

Got it, let's fix this sorting issue for your LastFM Discord command! Here's how you can sort that list of user-playcount strings in descending order based on the numeric value:

Step 1: Add a Helper Function to Extract Playcounts #

We need a way to pull the numeric playcount from each string in your wk list. We'll use a regular expression to find the number in each entry, then convert it to an integer to use as our sorting key.

Step 2: Sort the List Using the Helper Function #

Use Python's built-in sorted() function, passing our helper as the key parameter and setting reverse=True to get descending order.

Modified Code #

Here's your updated lastfm_whoknows function with the sorting logic added:

import re  # Make sure to import this at the top of your file

@lastfm.command(name="whoknows",aliases=['wk'],help="Who plays the artist most in a guild")
async def lastfm_whoknows(self,ctx:Context,*,artist:str=None):
    wk = []
    db = self.db["lastfm"]["lastfm"]
    to_find = {"m_id":ctx.author.id}
    found = db.find(to_find)
    for z in found:
        async with aiohttp.ClientSession() as session:
            params= {"api_key" : "ok", "user" : z["username"], "period" : "overall", "limit" : 1, "method":"user.getRecentTracks", "format":"json"}
            async with session.get(url="http://ws.audioscrobbler.com/2.0", params=params) as response:
                resp = await response.read()
                jsonData1 = json.loads(resp)
                for xy in ctx.guild.members:
                    db = self.db["lastfm"]["lastfm"]
                    to_find = {"m_id":xy.id}
                    found = db.find(to_find)
                    for x in found:
                        async with aiohttp.ClientSession() as session:
                            params= {"api_key" : "ok", "user" : x["username"], "artist" : jsonData1["recenttracks"]["track"][0]['artist']['#text'], "method":"artist.getInfo", "format":"json"}
                            async with session.get(url="http://ws.audioscrobbler.com/2.0", params=params) as response:
                                resp = await response.read()
                                jsonData = json.loads(resp)
                                alr = f'**{xy.name}** | **{jsonData["artist"]["stats"]["userplaycount"]}**'
                                wk.append(alr)
    
    # --- New Sorting Logic Starts Here ---
    def get_playcount(entry):
        # Split the string at the |, take the right part, then extract digits
        playcount_part = entry.split('|')[-1]
        match = re.search(r'\d+', playcount_part)
        return int(match.group()) if match else 0
    
    # Sort the list in descending order of playcount
    sorted_wk = sorted(wk, key=get_playcount, reverse=True)
    # --- New Sorting Logic Ends Here ---
    
    join = "\n".join(sorted_wk)
    em = discord.Embed(description=join,color=0xec1c24)
    await ctx.reply(embed=em, mention_author=False)

Quick Explanation #

• The get_playcount function splits each entry at the | character, grabs the part with the playcount, then uses regex to find the numeric value.
• sorted(wk, key=get_playcount, reverse=True) rearranges your list so entries with higher playcounts come first.
• We fall back to 0 if no number is found (just in case of API errors or malformed data).

Small Optimization Note #

You might want to move the aiohttp.ClientSession creation outside the nested loops—creating a new session for every member is inefficient. You could create one session at the start of the function and reuse it for all API calls!

内容的提问来源于stack exchange，提问作者Rohan