如果文件已经存在，为什么我的机器人不替换文件？

Question

我正在尝试关注tutorial，了解如何为不和谐构建音乐机器人。

我在 win10 上使用 pycharm 2021.1.1 和 anaconda 3 作为我的解释器（python 3.7）。

我添加了一些更改，但没有任何更改会导致此行为：机器人尝试下载但由于文件已存在而失败。该文件很可能是song.mp3，但它应该在该行中被删除：（我尝试了两个版本，都没有工作，我认为这是同一个问题）

1. 为什么文件song.mp3没有被删除？
2. 我是否犯过任何其他我不知道的错误并且会阻止机器人播放音乐？

if song_there:
#        os.remove('song.mp3')
        os.remove(os.path.join(os.getcwd(),"song.mp3"))

最少的代码：

import discord
from discord.ext import commands
import youtube_dl #for url music command
import os

client = commands.Bot(command_prefix = '><')

#play music from url
@client.command(aliases = ['p'])
async def playMusic(ctx, vcName, url : str): #play music file
    song_there = os.path.isfile('song.mp3')

    try:
        if song_there:
#            os.remove('song.mp3')
            os.remove(os.path.join(os.getcwd(),"song.mp3"))
    except PermissionError:
        await ctx.send('A song is currently playing')
        return

    ydl_opts = {
        'format': 'bestaudio/best',
        'postprocessors': [{
            'key': 'FFmpegExtractAudio',
            'preferredcodec': 'mp3',
            'preferredquality': '192',
        }]
    }
    with youtube_dl.YoutubeDL(ydl_opts) as ydl:
        ydl.download([url])
    for file in os.listdir('./'):
        os.rename(file, 'song.mp3')
    voice.play(discord.FFmpegPCAudio('song.mp3'))
    voiceChannel = discord.utils.get(ctx.guild.channels, name=str(vcName)) 
    await voiceChannel.connect()
    voice = discord.utils.get(client.voice_clients, guild=ctx.guild)
    client.run('token')

错误：

[youtube] bvNZeh6f8vE: Downloading webpage

[download] Destination: title-bvNZeh6f8vE.webm

[download] 100% of 3.95MiB in 00:00                  

[ffmpeg] Destination: title-bvNZeh6f8vE.mp3

Ignoring exception in command playMusic:

Traceback (most recent call last):

File "C:\ProgramData\Anaconda3\lib\site-packages\discord\ext\commands\core.py", line 85, in 
wrapped

ret = await coro(*args, **kwargs)

File "path/tut-bot.py", line 42, in playMusic
os.rename(file, 'song.mp3')

FileExistsError: [WinError 183] Cannot create a file when that file already exists: 'music bot 
1.py' -> 'song.mp3'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):

 File "C:\ProgramData\Anaconda3\lib\site-packages\discord\ext\commands\bot.py", line 939, in 
invoke

await ctx.command.invoke(ctx)

File "C:\ProgramData\Anaconda3\lib\site-packages\discord\ext\commands\core.py", line 863, in 
invoke

await injected(*ctx.args, **ctx.kwargs)

File "C:\ProgramData\Anaconda3\lib\site-packages\discord\ext\commands\core.py", line 94, in 
wrapped

raise CommandInvokeError(exc) from exc

discord.ext.commands.errors.CommandInvokeError: Command raised an exception: FileExistsError: 
[WinError 183] Cannot create a file when that file already exists: 'music bot 1.py' -> 
'song.mp3'

Deleting original file title-bvNZeh6f8vE.webm (pass -k to keep)

Answer 1

我认为它没有被删除的原因是因为你的song_there = os.path.isfile('song.mp3')尝试用song_there = os.path.exists('song.mp3')替换它，如果这个指向song.mp3的路径是正确的。

尝试使用os.path.exists() 代替os.path.isfile()，isfile() 仅返回True 给定路径是文件。