python object-oriented _2

self understanding

Popular understanding of self is an instance of an object, what is instantiated, self is what

Examples of variables: variables can be used through instantiation

class the Person ():
     DEF  the __init__ (Self, ID, name): # constructor 
        self.id ID = # instance variables of 
        the self.name name = # instance variables

    DEF Cook (Self):
         Print ( ' % S in cooking ' % the self.name)

    DEF housework (Self):
         Print ( ' % S housework ' % the self.name)

XH = the Person (. 1, ' black ' ) # is equivalent to __init (self, id, name) self actually XH 
xh.cook ()
xh.housework()
XB = the Person (2, ' white ' )
xb.cook()

Class variables: variables which are defined in the class, priority access to the object class instance variables, i.e. variables of the constructor, if the acquired class variables will not obtain

class Test:
    name = 'haha'
    def __init__(self,name):
        # self.name = name
        pass
    def test(self):
        print('姓名是%s'%self.name)

t=Test('ahah')
print(t.name)

Class methods: instance methods can not be called, the class name can be called directly, examples can also be called class methods can be called a class variable

class Test:

    name = 'haha'

    def __init__(self,name):
        # self.name = name
        pass

    DEF Test (Self):
         Print ( ' name is S% ' % the self.name)

    @classmethod # plus the decorator is to define a class method 
    DEF sayCountry (CLS):     # CLS itself representative of this class 'the Test' 
        Print (cls.name)

t=Test('ahah')
print(t.name)
Test.sayCountry () # class method, no examples of direct call by the class name; examples can also call with

Static method: You can not call the class variables, class methods can not be called; the class name can be called directly, examples can also call it directly

class Test:

    name = 'haha'

    def __init__(self,name):
        self.name = name


    DEF Test (Self):
         Print ( ' name is S% ' % the self.name)

    @classmethod # plus the decorator is to define a class method 
    DEF sayCountry (CLS):     # CLS itself representative of this class 'the Test' 
        Print (cls.name)

    @classmethod
    def getCountry(cls):
        cls.sayCountry () # class methods can invoke another 

    @staticmethod # plus the decorator is to define a static method, can not be called class variables and class methods 
    DEF Help ():
         Print ( ' manual ' )

t=Test('ahah')
print(t.name)
Test.sayCountry () # class method, no examples of direct call by the class name; with examples can also call 
Test.help ()
Test.getCountry()

Attribute methods: one looks like variable parameters can not

class Test:

    name = 'haha'

    def __init__(self,name,age):
        self.name = name
        self.age = age

    DEF Test (Self):
         Print ( ' name is S% ' % the self.name)

    @classmethod # plus the decorator is to define a class method 
    DEF sayCountry (CLS):     # CLS itself representative of this class 'the Test' 
        Print (cls.name)

    @classmethod
    def getCountry(cls):
        cls.sayCountry () # class methods can invoke another 

    @staticmethod # plus the decorator is to define a static method, can not be called class variables and class methods 
    DEF Help ():
         Print ( ' manual ' )

    @property
    DEF . price (Self): # property methods, can not use the parameter 
        Print (self.age)

t=Test('ahah',10)
print(t.name)
Test.sayCountry () # class method, no examples of direct call by the class name; with examples can also call 
Test.help ()
Test.getCountry()
t.price    # without parentheses, reference and reference attributes (variables) consistent