Python学习Day8--dict字典

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dict类

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info = {key:value}
字典的value可以为任何值
列表，字典不能作为字典的key
字典key按照哈希表来保存，key会转换成哈希值。
但是字典是无序的

通过索引[key]来找到指定元素
info = {
	'k1':18,
	 2 : True,
	'k3':[
	11,
	22,
	33,
	{
	'kk1':'vv1',
	'kk2':'vv2',
	'kk3':(11,22),
	}
	],
	'k4':(11,22,33,44)
}
v = info['k3'][3]['kk3'][1]
print(v)
输出结果：
22

支持for循环，但不支持while循环

info = {
	'k1':18,
	 2 : True,
	'k3':[
	11,
	22,
	33,
	{
	'kk1':'vv1',
	'kk2':'vv2',
	'kk3':(11,22),
	}
	],
	'k4':(11,22,33,44)
}
for i in info.keys():
	print(i)
输出结果：
k1
2
k3
k4

info = {
	'k1':18,
	 2 : True,
	'k3':[
	11,
	22,
	33,
	{
	'kk1':'vv1',
	'kk2':'vv2',
	'kk3':(11,22),
	}
	],
	'k4':(11,22,33,44)
}
for i in info.values():
	print(i)
输出结果：
18
True
[11, 22, 33, {'kk1': 'vv1', 'kk2': 'vv2', 'kk3': (11, 22)}]
(11, 22, 33, 44)

info = {
	'k1':18,
	 2 : True,
	'k3':[
	11,
	22,
	33,
	{
	'kk1':'vv1',
	'kk2':'vv2',
	'kk3':(11,22),
	}
	],
	'k4':(11,22,33,44)
}
for i in info.keys():
	print(i,info[i])
输出结果：
k1 18
2 True
k3 [11, 22, 33, {'kk1': 'vv1', 'kk2': 'vv2', 'kk3': (11, 22)}]
k4 (11, 22, 33, 44)

获取键值对

info = {
	'k1':18,
	 2 : True,
	'k3':[
	11,
	22,
	33,
	{
	'kk1':'vv1',
	'kk2':'vv2',
	'kk3':(11,22),
	}
	],
	'k4':(11,22,33,44)
}
for k,v in info.items():
	print(k,v)
输出结果：
k1 18
2 True
k3 [11, 22, 33, {'kk1': 'vv1', 'kk2': 'vv2', 'kk3': (11, 22)}]
k4 (11, 22, 33, 44)

支持del删除
如果key值重复，只取一个