UnboundLocalError：在赋值之前引用了局部变量“userOrder”，但是之前以类似的方式调用它没有错误

Question

I'm writing in python using the discord.py plugin. The very top of my code looks like this:

import random
import sqlite3
import discord
import shuffle as shf
import time
import os

client = discord.Client()

userOrder = []
roundOrder = []
turnPos = 0
joinedPlayers = 0
maxPlayers = 0
currentPlayer = 0
centerPot = 0

@client.event
async def on_ready():
    print("Logged in")
    print(userOrder, roundOrder, joinedPlayers, currentPlayer + "\n---")

@client.event
async def on_message(message):
    print(userOrder, roundOrder, joinedPlayers, currentPlayer)

The result when it is run is this:

Logged in
[] [] 0 0
---
Ignoring exception in on_message
Traceback (most recent call last):
  File "C:\Program Files (x86)\Python36-32\lib\site-packages\discord\client.py", line 333, in _run_event
    await coro(*args, **kwargs)
  File "C:\Users\Willi\Desktop\Python Projects\Discord Bots\Poker Bot\Poker Game.py", line 29, in on_message
    print(userOrder, roundOrder, joinedPlayers, currentPlayer)
UnboundLocalError: local variable 'userOrder' referenced before assignment

This confuses me because the first function on_ready() had no problem calling the global variable, whereas the second function, with the same indents and no extra code failed to call a global variable and thought I wanted a local variable.

Answer 1

You need to use globals or bot variables, I would recommend bot variables

Globals:

@client.event
async def on_ready():
    global userOrder, roundOrder, joinedPlayers, currentPlayer 
    print("Logged in")
    print(userOrder, roundOrder, joinedPlayers, currentPlayer + "\n---")

@client.event
async def on_message(message):
    global userOrder, roundOrder, joinedPlayers, currentPlayer 
    print(userOrder, roundOrder, joinedPlayers, currentPlayer)

Bot Variables:

client.userOrder = []
client.roundOrder = []
client.turnPos = 0
client.joinedPlayers = 0
client.maxPlayers = 0
client.currentPlayer = 0
client.centerPot = 0

@client.event
async def on_ready():
    print("Logged in")
    print(client.userOrder, client.roundOrder, client.joinedPlayers, client.currentPlayer + "\n---")

@client.event
async def on_message(message):
    print(client.userOrder, client.roundOrder, client.joinedPlayers, client.currentPlayer)