Object-oriented base (IV)

# Package attributes 
# a healthy person can be judged by whether the value bmi

class Person:
    def __init__(self,name,height,weight):
        self.name = name
        self.height = height
        self.weight = weight

    def bmi(self):
        return '{name}的bmi值为{date}'.format(name = self.name,date = round(self.weight / self.height ** 2,1))

p1 = Person('Tian',1.70,60)
print(p1.bmi())

# Here bmi is a property of the concept of a noun, this call is not in line with the rules

class Person:
    def __init__(self,name,height,weight):
        self.name = name
        self.height = height
        self.weight = weight
     # plus the following method decorator bmi became property methods 
    @Property
     DEF bmi (Self):
         return  ' {name} bmi value of DATE} { ' .format (name = the self.name, DATE = round (self.weight / self.height ** 2,1 ))

p1 = the Person ( ' Tian ' , 1.70,60 )
 Print (p1.bmi)
 # property can be changed but here we are a disguise of property so I can not change, this python there are other decorators

class Person:
    def __init__(self,name,height,weight):
        self.name = name
        self.height = height
        self.weight = weight
        self.__bmi = round(self.weight / self.height ** 2, 1)
    @property
    def bmi(self):
        return '{name}的bmi值为{date}'.format(name = self.name,date = self.__bmi)

    @ bmi.setter
    def bmi(self,num):
        self.__bmi = num

    @bmi.deleter
    def bmi(self):
        del self.__bmi
p1 = Person('Tian',1.70,60)
p1.bmi = 10
 Print (p1.bmi)
 del p1.bmi
 # Such modifications can, of course, is not such an approach will do no standardized calculation constructor, but here in this example

# Class methods 
class A:
    count = 20

    @classmethod
    def cal(cls,num):
        return num + cls.count

# Methods do not need this type of objects can be used to participate in the class method 
Print (A.CAL (15 ))



# Parent class to get a derived class can also be a class method 
class B (A):
    count = 30
print(B.cal(15))

# Class static method

class A:
    @staticmethod
    def func(user,pwd):
        if user == 'Tian' and pwd == 666:
            print('success')
        else:
            print('error')


A.func ( ' Tian ' , 666 )

# Increasing the reusability of code 
# make the block more clean and clear