Python instance methods, class methods, and Static methods

A normal method, the first parameter needs to be self, which represents a specific instance of itself.
If you use Staticmethod, you can ignore this self and use this method as a normal function.
For Classmethod, its first argument is not self, which is the CLS, which represents the class itself.
>>> class A (object):
def test1 (self):
Print "Hello", self
@staticmethod
Def test2 ():
print "Hello"
@classmethod
def test3 (CLS):
Print "Hello", CLS

>>> a = A ()
>>> A.test1 () #最常见的调用方式, but the same way as below
Hello <__main__. A Object at 0x9f6abec>
>>> A.test1 (A) #这里传入实例a, equivalent to the normal method of self
Hello <__main__. A Object at 0x9f6abec>
>>> A.test2 () #这里, because there are no parameters to the static method, it is possible to pass things
Hello
>>> a.test3 () #这里, because it is a class method, its first argument is the class itself.
Hello <class ' __main__. A ' >
>>> a #可以看到, enter a directly, and return the same information as the above call.
<class ' __main__. A ' >

Python instance methods, class methods, and Static methods