Discord.py音乐Bot音量存储报错：ValueError无效整数字面量

Hey there, let's figure out why you're hitting that ValueError and fix your volume persistence logic step by step.

Why the Error Happens #

The ValueError: invalid literal for int() with base 10: '' occurs because your code ends up reading an empty string from the file. Let's break down the problematic parts:

with open(r'E:\PythonProjects\WeebBot\textfiles\volumefile.txt', 'r+') as volumefile:
    open(r'E:\PythonProjects\WeebBot\textfiles\volumefile.txt', 'w')

• Opening the file with 'w' mode immediately clears all its content, wiping out any existing volume value.
• Even if you didn't clear the file, after writing a new value, the file pointer sits at the end of the file—so a direct read() call would return an empty string unless you move the pointer back to the start.
• Also, you don't need to manually call volumefile.close(): the with statement handles file closing automatically.

Fixed Volume Command Code #

Here's a cleaned-up, working version of your command with input validation and proper file handling:

@commands.command(pass_context=True, no_pm=True)
async def volume(self, ctx, value: int):
    """Sets the volume of the currently playing song (1-200%)."""
    # Validate input to avoid invalid volume values
    if not 1 <= value <= 200:
        await self.bot.say("Oops! Volume needs to be between 1 and 200.")
        return

    state = self.get_voice_state(ctx.message.server)
    volume_file_path = r'E:\PythonProjects\WeebBot\textfiles\volumefile.txt'

    # Save the new volume to the file (overwrites old value)
    with open(volume_file_path, 'w') as f:
        f.write(str(value))

    # Apply the volume to the current player if it's active
    if state.is_playing():
        player = state.player
        player.volume = value / 100  # Convert to 0.01-2.0 range
        await self.bot.say(f'Set volume to {value}%')

Persist Volume Across New Songs #

To make sure the saved volume applies every time a new track starts, add this logic to your play command/function:

# When initializing a new player for a song:
volume_file_path = r'E:\PythonProjects\WeebBot\textfiles\volumefile.txt'
try:
    with open(volume_file_path, 'r') as f:
        # Strip whitespace/newlines to avoid parsing issues
        saved_volume = int(f.read().strip())
        player.volume = saved_volume / 100
except (FileNotFoundError, ValueError):
    # Fallback to 50% if file is missing or has invalid content
    player.volume = 0.5
    # Optional: Create the file with default value for future use
    with open(volume_file_path, 'w') as f:
        f.write('50')

Key Improvements #

• Removed the redundant open() call that was clearing the file
• Added input validation to prevent invalid volume values outside the 1-200% range
• Simplified file saving with 'w' mode, which overwrites the old value cleanly
• Added error handling for playback logic to gracefully handle missing or empty files
• Eliminated unnecessary post-write file read—we can use the input value directly

Quick Note for Newer Discord.py Versions #

If you're using Discord.py v1.0+, ctx.message.server is deprecated. Replace it with ctx.guild to align with the latest API.

内容的提问来源于stack exchange，提问作者Bernas