Error importing package

[julio2000]

import discord
from discord.ext import commands

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

Token = 'a valid token'

@client.event
async def on_ready():
    print('bot is ready.')

client.run(Token)

Error:
Traceback (most recent call last):
  File "the location of the file", line 2, in <module>
    from discord.ext import commands
ModuleNotFoundError: No module named 'discord.ext'; 'discord' is not a package

I keep getting this error all of a sudden. An hour ago it was still working but now it just keeps on giving me this error. Has anyone got an idea why I get this error?

Thanks in advance!