import threading
def Thread(a):
    threading.Thread(target=a).start()
class abc(object):
    def __init__(self):
        self.asd()
    @Thread
    def asd(self):
        print 'This is a thread function'
abc()

<<< Traceback (most recent call last):
<<<   File "<string>", line 13, in <module>
<<<   File "<string>", line 9, in __init__
<<< TypeError: 'NoneType' object is not callable

import threading
def Thread(a):
    t1 = threading.Thread(target=a)
    t1.start()
@Thread
def ttt():
    print "This is a thread function"

from threading import Thread
def th(function):
	def decorate(*args, **kwargs):
		Thread(target = function(*args, **kwargs)).start()
	return decorate
class test1(object):
    def __init__(self):
        self.func1('test')
    @th
    def func1(self, *args):
        print args[0]
test1()

>>> def dec(func):
...     def g(*args, **kwargs):
...         return func(*args, **kwargs) * 2
...     return g
... 
>>> @dec
... def f1():
...     return 3
... 
>>> @dec
... def f2():
...     return 5
... 
>>> f1()
6
>>> f2()
10
>>>

from threading import Thread
def th(function):
    def decorate(*args, **kwargs):
        Thread(target = function, args = args).start()
    return decorate
class test1(object):
    def __init__(self):
        self.func1('test')
    @th
    def func1(self, *args):
        print args[0]
test1()

<<< test