py.面向对象,属性,类方法,静态方法,反射

例一:BMI指数(bmi是计算而来的,
# 但很明显它听起来像是一个属性而非方法,如果我们将其做成一个属性,更便于理解)
#
# 成人的BMI数值:
# 过轻:低于18.5
# 正常:18.5-23.9
# 过重:24-27
# 肥胖:28-32
# 非常肥胖, 高于32
#   体质指数(BMI)=体重(kg)÷身高^2(m)
#   EX:70kg÷(1.75×1.75)=22.86

# 1,初识属性:
# class A:
# def __init__(self, name, weight, height):
# self.name = name
# self.__weight = weight
# self.__height = height
#
# @property # 属性
# def bmi(self):
# return self.__weight / self.__height ** 2
#
#
#
# ly = A('女司机', 54, 1.6)
# print(ly.bmi)
#
# # 属性:将方法 伪装 成属性,虽然在代码层面上没有任何高深之处,
# # 但是让其看起来更合理.
# # 2,属性改,和删除.
#
# class Mes:
# def __init__(self, name, age,password):
# self.__name = name
# self.__age = age
# self.__password = password
#
# @property
# def password(self):
# '''对密码加密'''
# self.__password = hash(self.__password + '旭哥')
# return self.__password
#
# @password.setter
# def password(self,new_password):
# if type(new_password) is str:
# self.__password = new_password
# else:
# print('请输入字符串类型')
# @password.deleter
# def password(self):
# print(6666)
# # p1 = Mes('婉容', 18)
# # p1.name = '婉容蓉'
# # print(p1.name)
# # print(p1.name)
# p1 = Mes('婉容', 18,'hao123')
# # print(p1.password)
# 之前对属性的更改
# p1.name = 'alex'
# p1.password = '123456'
# print(p1.password)
# del p1.password
# print(p1.password)
# 第一步,对属性进行改操作,自动执行 被这个@password.setter装饰器装饰的方法
# 第二步,将新值传给这个被@password.setter装饰器装饰的方法里面,当做参数.

# property ***
# @password.setter *
# @password.deleter
#
# class Mes:
# def __init__(self, name, age,password):
# self.name = name
# self.__age = age
# self.__password = password
#
# @property
# def password(self):
# return self.__password
#
# @password.setter
# def password(self,new_password):
# self.__password = new_password
#
# @password.deleter
# def password(self):
# del self.__password
#
# p1 = Mes('婉容', 18, 'hao123')
# p1.name = 'alex'
# print(p1.name)
# print(p1.password)
# p1.password = '123456' # 这是是行代码,没有真正的改.
# print(p1.password)
# del p1.password
# print(p1.password)

# 商品类 封装商品名,商品原价, 商品折扣 定义一个方法,计算商品现价.

# class Goods:
# def __init__(self,name,original_price,discount):
# self.name = name
# self.__original_price = original_price
# self.__discount = discount
#
# @property
# def price(self):
# return self.__original_price * self.__discount
#
# @property
# def original_price(self):
# return self.__original_price
#
# @original_price.setter
# def original_price(self,new_original_price):
# self.__original_price = new_original_price
#
# apple = Goods('苹果',5,0.95)
# # print(apple.price)
# apple.original_price = 10
# print(apple.price)


# 类方法,静态方法

class A:
__name = 'alex'
def func(self):
print(self,'in func')

@classmethod # 类方法
def func1(cls):
print(cls, 'in func1')

def change(self,new_name):
A.__name = new_name
return A.__name
@classmethod
def change(cls,new_name):
A.__name = new_name
return A.__name

a1 = A()
a1.func()
A.func(a1)

# 类名去调用类方法,自动将类的空间传给类方法中的cls
# 对象如果调用类方法,自动将类空间传给类中的cls
A.func1()
a1.func1()
# 什么情况下使用类方法?
# 直接让类去操作类中的方法,没有必要创建对象在操作的时候,用类方法.
# a2 = A()
# print(a2.change('wusir'))
# # print(A.change(111,'wusir'))
# print(A.change('wusir'))
# 静态方法

# class A:
# __name = 'alex'
# def func(self):
# print(self,'in func')
#
# @classmethod # 类方法
# def func1(cls):
# print(cls, 'in func1')
#
#
# @staticmethod # 静态方法
# def login(username,password):
# print('登录成功...')
#
# A.login('alex', '123')

# 静态方法:在类中定义一个静态方法,无需传入你的类空间,对象空间,可以当成普通函数去用.


反射"""""""
 反射
# 非常非常非常非常重要的方法.
# 通过 字符串 操作一个空间 (对象).
# getattr()
# hasattr()
# setattr()
# delattr()

# 1,实例化一个对象去研究
# class A:
# country = 'China'
#
# def __init__(self, name, age):
# self.name = name
# self.age = age
#
#
# a1 = A('alex', 1000)
# print(a1.name)
# print(getattr(a1,'name1')) 从对象中得到这个属性对应的值
# print(hasattr(a1,'age')) 判断此对象中,有没有这个属性
# setattr(a1,'sex','男')
# setattr(a1,'name','wusir')
# print(getattr(a1,'name'))
# print(getattr(a1,'sex')) # 对一个对象设置属性
# delattr(a1,'name') # 对一个对象属性删除
# print(getattr(a1,'name'))

# if hasattr(a1,'name1'):
# getattr(a1,'name1')
# else:
# print('没有...')


# 2,类中去研究.
# class A:
# country = 'China'
# job = 'student'
#
# def __init__(self, name, age):
# self.name = name
# self.age = age
# def func(self):
# print('in func')
# print(getattr(A,'country1',False))
# if getattr(A,'country1',False):
# content = input('>>>').strip() # country
# print(A.content) #(A.'country')

# name = '1 + 2'
# name2 = 'name'
# print(eval(name2))


# print(A.country)
# print(A.content)
# print(eval('1+ 2'))

# content = input('>>>').strip() # 'country'
# 你拿到的是一个字符串类型,然后你又想对这个类进行操作
# if hasattr(A,content):
# print(getattr(A,content))

# print(getattr(A,'job1','没有此值'))
# print(getattr(A,'func'))
# getattr(A,'func')(11)

# 3,其他模块去研究.
import oldboy
print(oldboy.B.name_list)

bobj = getattr(oldboy,'B')
print(getattr(bobj,'name_list'))
#
print(getattr(oldboy.B,'name_list'))

print(getattr(oldboy.B,'add')(3,4))
print(getattr(oldboy,'login')('alex','123'))
# def func():
# pass
# print(func())


# 4,本模块(本文件)去研究.
# import sys
# def login():
# print(55)
#
# def func3():
# print(333)
#
# # content = input(">>>")
# # print(content()) # 这样错的
# print(sys.modules[__name__])
# getattr(sys.modules[__name__],'login')()
"
posted @ 2018-07-04 23:21  大海无量,苦海无边  阅读(414)  评论(0编辑  收藏  举报