how to send a tuple value as an arg to a function started as a thread?

I have a class function that I want to start up as a thread. The function takes as its argument a tuple value. The function works fine but my initial setup throws a TypeError. Here's some sample code:

import threading

class Test:
    def __init__(self):
        t = threading.Thread(target=self.msg, args=(2,1))
        t.start()
        print "started thread"

    # msg takes a tuple as its arg (e.g. tupleval = (0,1))
    def msg(self,tupleval):
        if(tupleval[0] > 1):
            print "yes"
        else:
            print "no"


test = Test()
test.msg((2,2))
test.msg((0,0))

and then the output is as follows:

started thread
yes
no
Exception in thread Thread-1:
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/threading.py", line 532, in __bootstrap_inner
    self.run()
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/threading.py", line 484, in run
    self.__target(*self.__args, **sel开发者_如何学JAVAf.__kwargs)
TypeError: msg() takes exactly 2 arguments (3 given)

It appears to work for the two explicit calls at the end, but the initial setup call throws the TypeError. I've tried packing values into a tuple in all sorts of ways but can't get rid of the error. Ideas?

args takes a tuple of arguments to pass to the function. When you say args=(2,1) you're not telling it to call msg with a single argument (2,1); you're telling it to call it with two arguments, 2 and 1.

You want args=((2,1),).

This is going to look really ugly, but I believe it should be args=((2,1),) (or args=[(2,1)] might look slightly nicer).

args is supposed to be a tuple of all the arguments to the function, so to pass a tuple, you need a tuple of a tuple. In addition, Python requires you to add the extra comma for a tuple with one element to differentiate it from just wrapping an expression with parentheses.