modify the magic method,extend the dict becomes a multi tree

master
gaufung 2017-01-03 10:17:21 +08:00
parent 3c0ddf3530
commit d1cc1fac2b
1 changed files with 12 additions and 8 deletions

View File

@ -22,25 +22,29 @@ class People(object):
print("\t".join([str(item) for item in sorted([People("abc", 18), People("abe", 19), People("abe", 12), People("abc", 17)])]))
# Python实现任意深度的赋值 例如a[0] = 'value1'; a[1][2] = 'value2'; a[3][4][5] = 'value3'
# Python实现任意深度的赋值 例如a[0] = 'value1'; a[0][2] = 'value2'; a[0][2][3] = 'value3',构造出一颗多叉树类似结构
class MyDict(dict):
def __init__(self,name=''): # 增加初始化函数将需要放置的value存储到内部中
self.name=name
def __str__(self): # 增加 __str__ 函数,将存储的元素输出出来
return self.name
def __setitem__(self, key, value): # 该函数不做任何改动 这里只是为了输出
print("setitem:", key, value, self)
super().__setitem__(key, value)
temp = MyDict(value)
super(MyDict,self).__setitem__(key, temp)
return
def __getitem__(self, item): # 主要技巧在该函数
print("getitem:", item, self)
# 基本思路: a[1][2]赋值时 需要先取出a[1] 然后给a[1]的[2]赋值
if item not in self: # 如果a[1]不存在
temp = MyDict() # 则需要新建一个dict
super().__setitem__(item, temp) # 并使得a[1] = dict
temp = MyDict(item) # 则需要新建一个dict
super(MyDict,self).__setitem__(item, temp) # 并使得a[1] = dict
return temp # 返回a[1] 使得a[1][2] = value有效
return super().__getitem__(item) # 如果a[1]存在 则直接返回a[1]
return super(MyDict,self).__getitem__(item) # 如果a[1]存在 则直接返回a[1]
# 使用例子:
test = MyDict()
test[0] = 'test'
test[1][2] = 'test1'
test[3][4][5] = 'test2'
test[0][2] = 'test1'
test[0][2][5] = 'test2'