class MyClass: def method(self): """ Instance methods need a class instance and can access the instance through `self`. """ return 'instance method called', self @classmethod def classmethod(cls): """ Class methods don't need a class instance. They can't access the instance (self) but they have access to the class itself via `cls`. """ return 'class method called', cls @staticmethod def staticmethod(): """ Static methods don't have access to `cls` or `self`. They work like regular functions but belong to the class's namespace. """ return 'static method called'
# All methods types can be # called on a class instance: obj = MyClass() obj.method() ('instance method called', <MyClass instance at 0x1019381b8>) obj.classmethod() ('class method called', <class MyClass at 0x101a2f4c8>) obj.staticmethod() 'static method called'
# Calling instance methods fails # if we only have the class object: >>> MyClass.classmethod() ('class method called', <class MyClass at 0x101a2f4c8>) >>> MyClass.staticmethod() 'static method called' >>> MyClass.method() TypeError: "unbound method method() must be called with MyClass " "instance as first argument (got nothing instead)"