多谢版友解释，原T1 decorator产生出来的是class
结果跟下面差不多，因为func不是function，所以
不会变成method，所以也就不会自动带入self.
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class T1(object): pass
class A(object):
def f(self): pass
print(type(f)) # <class 'function'>
func = T1()
print(type(func)) # <class '__main__.T1'>
a = A()
print(type(a.f)) # <class 'method'>
print(type(a.func)) # <class '__main__.T1'>
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