day25

1.封裝

"""
1、封裝（略）
2、在封裝的基礎上，我可以將裝到物件或者類中的屬性給隱藏起來
注意：
   （1）在定義類或者初始化物件時，在屬性前加__,就會將該屬性隱藏起來
     但該隱藏起始只是一種變形_類名__屬性名，並沒有真的隱藏起來
​
   （2）該變形操作是在類定義階段掃描語法時發生的變形，類定義之後新增的__開頭的屬性不會發生變形
​
   （3）該隱藏是對外不對內
​
   (4) 在繼承中，父類如果不想讓子類覆蓋自己的方法，可以將方法定義為私有的？？？
"""
# 例1
# class Student:
#   __school = "oldboy"  # _Student__school = "oldboy"
 
#
#   def __init__(obj, x, y, z):
#     obj.__name = x  # obj._Student__name = x
#     obj.age = y
#     obj.gender = z
#
#   def __choose(self):  # obj._Student__choose
#     print("%s 正在選課" %self.name)
#
# stu_obj1 = Student("馮瘋子", 18, "female")
# stu_obj1.__x=111
# print(stu_obj1.__dict__)
# print(stu_obj1.__x)
 
​
# print(stu_obj1.__dict__)
# print(stu_obj1._Student__name)
​
# print(Student.__dict__)
# print(Student._Student__school)
# print(stu_obj1._Student__school)
​
# 隱藏屬性的意義何在
# 1、把資料屬性隱藏起來的意義是：在類內開放介面，讓外界使用者通過介面來操作屬性值，我們可以在介面之上附加任意的邏輯
#                來嚴格控制外界使用者對屬性的操作
​
# class Student:
#   __school = "oldboy"  # _Student__school = "oldboy"
 
#
#   def __init__(obj, x, y, z):
#     obj.__name = x  # obj._Student__name = x
#     obj.__age = y
#     obj.gender = z
#
#   def __choose(self):  # obj._Student__choose
#     print("%s 正在選課" % self.name)
#
#   def get_name(self):
#     print(self.__name)  # print(self._Student__name)
#
#   def set_age(self,x):
#     if type(x) is not int:
#       print("年齡必須是整型，傻叉")
#       return
#     self.__age = x
#
#   def get_age(self):
#     print(self.__age)
#
#   def del_age(self):
#     del self.__age
#
# stu_obj1 = Student("馮瘋子", 18, "female")
# # stu_obj1.get_name()
#
#
# # stu_obj1.set_age("asfdasfdasfafd")
# stu_obj1.set_age(19)
# stu_obj1.get_age()
# # print(stu_obj1.__dict__)
​
# 2、把功能屬性隱藏起來:隔離複雜度
# class ATM:
#   def __card(self):
#     print('插卡')
#   def __auth(self):
#     print('使用者認證')
#   def __input(self):
#     print('輸入取款金額')
#   def __print_bill(self):
#     print('列印賬單')
#   def __take_money(self):
#     print('取款')
#
#   def withdraw(self):
#     self.__card()
#     self.__auth()
#     self.__input()
#     self.__print_bill()
#     self.__take_money()
#
# a=ATM()
# a.withdraw()

2.property

# 例1
# class People:
#   def __init__(self, name, height, weight):
#     self.name = name
#     self.height = height
#     self.weight = weight
#
#   @property
#   def bmi(self):
#     return self.weight / (self.height ** 2)
#
# p = People('egon', 1.81, 70)
# p.height = 1.84
# print(p.bmi())
​
# 例2
# class Student:
#   __school = "oldboy"  # _Student__school = "oldboy"
#
#   def __init__(obj, x, y, z):
#     obj.__name = x
#     obj.__age = y
#     obj.gender = z
#
#   def get_name(self):
#     print("訪問控制")
#     return self.__name
#
#   def set_name(self,x):
#     print("賦值控制")
#     self.__name = x
#
#   def del_name(self):
#     print("刪除控制")
#     del self.__name
#
#   def get_age(self):
#     return self.__age
#
#   def set_age(self, x):
#     if type(x) is not int:
#       print("年齡必須是整型，傻叉")
#       return
#     self.__age = x
#
#   def del_age(self):
#     print("不讓刪")
#
#
#   age = property(get_age, set_age, del_age)
#   name = property(get_name, set_name, del_name)
#
#
# stu_obj1 = Student("馮瘋子", 18, "female")
#
# # print(stu_obj1.age)
# # stu_obj1.age = "19"
# # del stu_obj1.age
# # print(stu_obj1.age)
#
#
# print(stu_obj1.name)
# # stu_obj1.name="EGON"
# # del stu_obj1.name
​
# 例3:
class Student:
  __school = "oldboy" # _Student__school = "oldboy"
​
  def __init__(obj, x, y, z):
    obj.__name = x
    obj.__age = y
    obj.gender = z
​
  @property
  def name(self):
    print("訪問控制")
    return self.__name
​
  @name.setter
  def name(self, x):
    print("賦值控制")
    self.__name = x
​
  @name.deleter
  def name(self):
    print("刪除控制")
    del self.__name
​
​
stu_obj1 = Student("馮瘋子", 18, "female")
​
stu_obj1.name

3.繫結方法與非繫結方法

# 類中的定義的函式
# 1 繫結方法:誰來呼叫就會將誰當作第一個引數傳入
#  (1)繫結給物件的方法:類中定義的函式預設就是繫結給物件的方法,應該是由物件呼叫,會把物件當作第一個引數傳入
#  (2)繫結給類的方法:在類中的函式上加一個裝飾器@classmethod,該函式就繫結給類了,應該是由類來呼叫,會把類當作第一個引數傳入
​
# 2 非繫結方法:既不與類繫結也不與物件繫結,就是一個普通的函式,誰都可以來呼叫,沒有自動傳參的效果,
#  在函式上新增裝飾器@staticmethod
#
# class People:
#   def __init__(self, name, age):
#     self.name = name
#     self.age = age
#
#   def tell_info(self):
#     print("<%s:%s>" % (self.name, self.age))
#
#   @classmethod
#   def f1(cls):
#     print(cls)
#
#   @staticmethod
#   def f2(x,y,z):
#     print(x,y,z)
#
#
# p1=People('egon',18)
# # p1.tell_info()
#
# # print(p1.tell_info)
# # print(People.f1)
#
# # People.f1()
#
# # print(p1.f2)
# # print(People.f2)
# p1.f2(1,2,3)
# People.f2(1,2,3)
​
# 例如:
import uuid
import settings
​
class MySQL:
  def __init__(self,ip,port):
    self.mid = self.__create_id()
    self.ip = ip
    self.port = port
​
  def tell_info(self):
    print("%s:<%s:%s>" %(self.mid,self.ip,self.port))
​
  @staticmethod
  def __create_id():
    return uuid.uuid4()
​
  @classmethod
  def from_conf(cls):
    return cls(settings.IP, settings.PORT)
​
# obj = MySQL("10.10.11.11",3306)
# obj.tell_info()
​
​
obj1=MySQL.from_conf()
obj1.tell_info()