Question
What is the difference between a function decorated with @staticmethod and one decorated with @classmethod?
Answer:
Maybe a bit of example code will help: Notice the difference in the call signatures of foo, class_foo and static_foo:
- class A(object):
- def foo(self,x):
- print "executing foo(%s,%s)"%(self,x)
- @classmethod
- def class_foo(cls,x):
- print "executing class_foo(%s,%s)"%(cls,x)
- @staticmethod
- def static_foo(x):
- print "executing static_foo(%s)"%x
With @classmethod, the class of the object instance is implicitly passed as the first argument instead of self.
You can also call class_foo using the class. In fact, if you define something to be a @classmethod, it is probably because you intend to call it from the class rather than from a class instance. One use people have found for class methods is to create inheritable alternative constructors.
With @staticmethod, neither self (the object instance) nor cls (the class) is implicitly passed as the first argument. They behave like plain functions except that you can call them from an instance or the class:
Staticmethods are used to group functions which have some logical connection with a class to the class.
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