coding: utf-8

#########################################################################

网站: <a href="http://www.crazyit.org">疯狂Java联盟</a>

author yeeku.H.lee kongyeeku@163.com

version 1.0

Copyright (C), 2001-2018, yeeku.H.Lee

This program is protected by copyright laws.

Program Name:

Date:

#########################################################################
class Rectangle:
def init (self, width, height):
self.width = width
self.height = height
def setattr(self, name, value):
print('----设置%s属性----' % name)
if name == 'size':
self.width, self.height = value
else:
self.dict[name] = value
def getattr(self, name):
print('----读取%s属性----' % name)
if name == 'size':
return self.width, self.height
else:
raise AttributeError
def delattr(self, name):
print('----删除%s属性----' % name)
if name == 'size':
self.dict['width'] = 0
self.dict['height'] = 0

rect = Rectangle(3, 4)
print(rect.size)
rect.size = 6, 8
print(rect.width)
del rect.size
print(rect.size)

自带的函数：hasattr setattr getattr

image.png

call

image.png

len getitem setitem

image.png

coding: utf-8

def check_key (key):
'''
该函数将会负责检查序列的索引，该索引必须是整数值，否则引发TypeError
且程序要求索引必须为非负整数，否则引发IndexError
'''
if not isinstance(key, int): raise TypeError('索引值必须是整数')
if key < 0: raise IndexError('索引值必须是非负整数')
if key >= 26 ** 3: raise IndexError('索引值不能超过%d' % 26 ** 3)
class StringSeq:
def init(self):
# 用于存储被修改的数据
self.__changed = {}
# 用于存储已删除元素的索引
self.__deleted = []
def len(self):
return 26 ** 3
def getitem(self, key):
'''
根据索引获取序列中元素
'''
check_key(key)
# 如果在self.__changed中找到已经修改后的数据
if key in self.__changed :
return self.__changed[key]
# 如果key在self.__deleted中，说明该元素已被删除
if key in self.__deleted :
return None
# 否则根据计算规则返回序列元素
three = key // (26 * 26)
two = ( key - three * 26 * 26) // 26
one = key % 26
return chr(65 + three) + chr(65 + two) + chr(65 + one)
def setitem(self, key, value):
'''
根据索引修改序列中元素
'''
check_key(key)
# 将修改的元素以key-value对的形式保存在__changed中
self.__changed[key] = value
def delitem(self, key):
'''
根据索引删除序列中元素
'''
check_key(key)
# 如果__deleted列表中没有包含被删除key，添加被删除的key
if key not in self.__deleted : self.__deleted.append(key)
# 如果__changed中包含被删除key，删除它
if key in self.__changed : del self.__changed[key]