标签：object push round python setter .text 魔术方法 指定 family
【主要内容】主要总结书中关于类和对象的简单程序，用于说明类的基本使用方法
注意：6.类中变量的私有保护 9.魔术方法
【基本知识】
1.类的基本定义
1 class Person():
2 def __init__(self,name): #初始化方法，注意类中方法的第一个参数为表示自身的self
3 self.name = name
4 hunter = Person("Elmer Fudd")
5 print(hunter.name)
2.继承
1 class Car():
2 def exclaim(self):
3 print("I‘m a car!")
4
5 class Yugo(Car):
6 pass
7 give_me_a_yugo = Yugo()
8 give_me_a_yugo.exclaim()
9 #输出：I‘m a car!
3.覆盖
1 class Car():
2 def exclaim(self):
3 print("I‘m a car!")
4
5 class Yugo(Car):
6 def exclaim(self):
7 print("I‘m a yugo!")
8 give_me_a_car = Car()
9 give_me_a_yugo = Yugo()
10 give_me_a_car.exclaim()
11 give_me_a_yugo.exclaim()
12 #输出:I‘m a car!
13 # I‘m a yugo!
4.添加新方法
1 class Car():
2 def exclaim(self):
3 print("I‘m a car!")
4
5 class Yugo(Car):
6 def exclaim(self):
7 print("I‘m a yugo!")
8 def need_a_push(self):
9 print("A little help here?")
10
11 give_me_a_car = Car()
12 give_me_a_yugo = Yugo()
13 #give_me_a_car.need_a_push()
14 give_me_a_yugo.need_a_push()
5.使用super调用父类的函数
下面的例子中，子类将父类的__init__()方法覆盖，需要显示调用
1 class Person():
2 def __init__(self,name):
3 self.name = name
4
5 class EmailPerson(Person):
6 def __init__(self,name,email):
7 super().__init__(name)
8 self.email = email
9
10 bob = EmailPerson("Bob Frapples","bob@frapples,com")
11 print(bob.name)
12 print(bob.email)
6.类的私有保护性
方法一、定义get和set方法后利用property()函数设置属性
1 class Duck():
2 def __init__(self, input_name):
3 self.hidden_name = input_name
4 def set_name(self, input_name):
5 print("inside the setter")
6 self.hidden_name = input_name
7 def get_name(self):
8 print("inside the getter")
9 return self.hidden_name
10 name = property(get_name,set_name)
11
12 fowl = Duck("howard")
13 fowl.name
14 fowl.get_name()
15 fowl.set_name("Dafft")
通过property函数设置set和get函数可以设置新的name属性
但是，仍然可以通过hidden_name调用
方法二、使用装饰器
@property,用于指示getter方法
@name.setter,用于指示setter方法
1 class Duck():
2 def __init__(self, input_name):
3 self.hidden_name = input_name
4 @property
5 def name(self):
6 print("inside the getter")
7 return self.hidden_name
8 @name.setter
9 def name(self, input_name):
10 print("inside the setter")
11 self.hidden_name = input_name
12 fowl = Duck("howard")
13 fowl.name = "Donald"
14 print(fowl.hidden_name)
注意：仍然可以通过hidden_name调用
方法三、私有命名
#变量由连续两个下划线开头(__)
1 class Duck():
2 def __init__(self,input_name):
3 self.__name = input_name
4 @property
5 def name(self):
6 return self.__name
7 @name.setter
8 def name(self,input_name):
9 self.__name = input_name
10
11 fowl = Duck("Marry")
12 print(fowl.name)
13 fowl.name = "Jack"
14 print(fowl.name)
注意：无法访问fowl.__name，但是可以通过fowl._Duck__name访问。
7.函数的类型
（1）实例方法：以self为第一个参数的方法。调用时会将调用该方法对象作为self参数传入。（参见上述函数）
（2）类方法：作用于整个类。用前缀@classmethod指定，第一个参数为类本身（cls）
1 class A(): 2 count = 0 3 def __init__(self): 4 A.count += 1 5 @classmethod 6 def kids(cls): 7 print("A has" , cls.count, "little objects.") 8 9 a1 = A() 10 a2 = A() 11 a3 = A() 12 A.kids()
（3）静态方法：@staticmethod不影响类也不影响方法
1 class CoyoteWeapon(): 2 @staticmethod 3 def commercial(): 4 print("This is a static method") 5 6 CoyoteWeapon.commercial()
【思考】2、3其实就类似于C++中的static方法
8.多态
1 class Quote(): 2 def __init__(self,person,word): 3 self.person = person 4 self.word = word 5 def who(self): 6 return self.person 7 def says(self): 8 return self.word+‘.‘ 9 10 class QuestionQuote(Quote): 11 def says(self): 12 return self.word+‘?‘ 13 14 class ExclamationQuote(Quote): 15 def says(self): 16 return self.word+‘!‘ 17 18 class BabblingBrook(): 19 def who(self): 20 return "777" 21 def says(self): 22 return "888" 23 24 def printQuote(obj): 25 print(obj.who(), ‘says:‘, obj.says()) 26 27 hunter1 = Quote("Quote1","Quote1") 28 hunter2 = QuestionQuote("QuestionQuote1","QuestionQuote1") 29 hunter3 = ExclamationQuote("ExclamationQuote1","ExclamationQuote1") 30 babblingbrook = BabblingBrook() 31 printQuote(hunter1) 32 printQuote(hunter2) 33 printQuote(hunter3) 34 printQuote(babblingbrook)
注：BabblingBrook不是子类但仍可以调用
9.魔术方法：类似于C++中的operator方法
1 class Word(): 2 def __init__(self,text): 3 self.text = text 4 def __eq__(self,word2): 5 return self.text.lower() == word2.text.lower() 6 7 first = Word("HA") 8 second = Word("ha") 9 print(first == second)
标签：object push round python setter .text 魔术方法 指定 family
原文地址：http://www.cnblogs.com/daixianqiang414/p/7282218.html
