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02.property.py
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74 lines (54 loc) · 1.9 KB
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# -*- coding: utf-8 -*-
"""
@description: 属性
@author:XuMing
"""
from __future__ import print_function # 兼容python3的print写法
from __future__ import unicode_literals # 兼容python3的编码处理
# 只读属性
class Clothes(object):
def __init__(self, price):
self.price = price
# 这样 discount_price 就变成属性了
@property
def discount_price(self):
return self.price * 0.8
# 这里 discount_price 就是一个只读不写的属性了（注意是属性不是方法）,
# 而price是可读写的属性：
my_clothes = Clothes(100)
print(my_clothes.discount_price) # 80.0
# 可以修改price属性来改变discount_price：
my_clothes.price = 200
print(my_clothes.discount_price) # 160.0
# my_clothes.discount_price()会报错，因为 my_clothes.discount_price 是属性，不是方法；
# my_clothes.discount_price=100 也会报错，因为只读
# 对于 @property 生成的只读属性，
# 我们可以使用相应的 @attr.setter 修饰符来使得这个属性变成可写的：
class Clothes(object):
def __init__(self, price):
self.price = price
# 这样就变成属性了
@property
def discount_price(self):
return self.price * 0.8
@discount_price.setter
def discount_price(self, new_price):
self.price = new_price * 1.25
# example:
my_clothes = Clothes(100)
print(my_clothes.discount_price)
my_clothes.price = 200
print(my_clothes.discount_price)
# 修改 discount_price 属性：
my_clothes.discount_price = 180
print(my_clothes.price)
print(my_clothes.discount_price)
# 一个等价的替代如下，用方法：
class Clothes(object):
def __init__(self, price):
self.price = price
def get_discount_price(self):
return self.price * 0.8
def set_discount_price(self, new_price):
self.price = new_price * 1.25
discount_price = property(get_discount_price, set_discount_price)