UnboundLocalError：分配前已引用本地变量“用户”

Question

This is part of a code that runs a moderator bot in a chatroom i use. This section of the code is to approve someone's request to cam up but whenever I use the command I get this unbound local error... I have gone through this so many times and I can't figure out why I'm getting it.

def approveCam(room, identifier):
    if not room.bpass:
        return

    if type(identifier) in [str, unicode, int]:
        user = room._getUser(identifier)
        if not user:
            return "User " + str(identifier) + " was not found..."

    if user.broadcasting:
        return

    room._sendCommand("privmsg", [room._encodeMessage("/allowbroadcast " + room.bpass),
    "#0,en" + "n" + str(user.id) + "-" + user.nick])

The problem seems to be at "if user.broadcasting:"

the code worked on a previous version of the bot like this

def approveCam(room, user):
    if type(user) is str or type(user) is unicode:
        nick = user
        user = room._getUser(user)
    if not user:
        return "User "+nick+" was not found..."

    if not room.bpass:
        return

    room._sendCommand("privmsg", [room._encodeMessage("/allowbroadcast "+room.bpass),
    "#0,en"+"n"+ user.id+"-"+user.nick])

and here is the response i get in command prompt when i try to run the command.

Traceback (most recent call last):
 File "C:\Users\Ejah\Downloads\Desktop\Tunebot-Master\tinychat.py", line     1262
in onMessage
  SETTINGS['onMessageExtend'](self, user, msg)
 File "tunebot.py", line 1316, in onMessageExtended
  handleUserCommand(room, user, msg)
 File "tunebot.py", line 1722, in handleUserCommand
  res = botterCommands(room, userCmd, userArgsStr, userArgs, target,
 File "tunebot.py", line 2786, in botterCommands
  res = approveCam(room, user)
 File "tunebot.py", line 4043, in approveCam
  if user.broadcasting:
UnboundLocalError: local variable 'user' referenced before assignment"

Answer 1

Update your code to raise an error when identifier is of an invalid type and all will become clear:

def approveCam(room, identifier):
    if not room.bpass:
        return

    if type(identifier) in [str, unicode, int]:
        user = room._getUser(identifier)
        if not user:
            return "User " + str(identifier) + " was not found..."
    else:
        raise ValueError('Invalid type for identifier')

    if user.broadcasting:
        return

    room._sendCommand("privmsg", [room._encodeMessage("/allowbroadcast " + room.bpass),
        "#0,en" + "n" + str(user.id) + "-" + user.nick])

Answer 2

user.broadcasting - This is not correct

At this point user does not exist and hence the interpreter won't allow that. You must initialise local variables before using them.

Make user a global variable with some value to it.

Answer 3

Probably if type(identifier) in [str, unicode, int]: is False , so the body of the if is not executed and user is never inizialized.

Initialize user before the second if if possible, or rethink your code.

PS Don't use getter and setter! Python is not Java, if you really need to use them, use a property instead.