1
2
3
4
5
6
7
8
9
10
| class MyDict(dict):
def __init__(self):
super(MyDict, self).__init__()
self.li = []
md = MyDict()
md["k1"] = 123
md["k2"] = 456
print(md)
|
在不破坏字典对象构造方法的情况下，自定义创建一个列表，用来存放key
1
2
3
4
5
6
7
8
| class MyDict(dict):
def __init__(self):
super(MyDict, self).__init__()
self.li = []
def __setitem__(self, key, value):
self.li.append(key)
super(MyDict, self).__setitem__(key, value)
|
将新的键值对保存到字典的时候，保存它的key到我们自定义创建的列表中
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
| class MyDict(dict):
def __init__(self):
super(MyDict, self).__init__()
self.li = []
def __setitem__(self, key, value):
self.li.append(key)
super(MyDict, self).__setitem__(key, value)
def __str__(self):
tmp_list = []
for key in self.li:
value = self.get(key)
tmp_list.append("'%s': %s" % (key, value))
tmp_str = "{" + ", ".join(tmp_list) + "}"
return tmp_str
md = MyDict()
md["k1"] = 123
md["k2"] = 456
print(md)
------------
{'k1': 123, 'k2': 456}
|
