python08字典

a = 10
b = a
print(id(a)) # 打印a的内存地址
print(id(b))
b = 15
print(id(b))

不可变类型：整型、字符串、元组

可变类型：列表、字典

dic = {‘name’: ‘LPL’, ‘age’: 26, ‘hobby’: ‘game’, ‘isHandsome’: True}
print(dic)

字典两大特点： 无序，键唯一

d = dict(((‘name’, ‘LPL’), )) # 新建字典的两种类型
print(d)

dic1 = {‘name’: ‘LPL’, ‘age’: 23}

dic1[‘age’] = 26
print(dic1)

ret = dic1.setdefault(‘age’, 55) # 键存在，不改动，返回字典中该键的键值
print(ret)

ret2 = dic1.setdefault(‘hobby’, ‘game’) # 键不存在，在字典中插入新的键值对
print(ret2)

字典查询

print(dic1[‘name’])
print(dic1.keys())
print(dic1.values())
print(list(dic1.keys()))

字典更新

dic2 = {‘name’: ‘LPL’, ‘age’: ‘22’}
dic3 = {1: 1111, 2: 222}
dic2.update(dic3)
print(dic2)
print(dic3)

删除

dic5 = {‘name’: ‘LPL’, ‘age’: ‘22’, ‘dic’: 5, 1: 1111, 2: 22222}
del dic5[‘age’]
print(dic5)

res = dic5.pop(‘name’)
print(dic5)
print(res)

dic5.popitem() # 随机删除
print(dic5)

dic5.clear() # 清除字典所有
print(dic5)

dic6 = dict.fromkeys([‘host1’, ‘host2’, ‘host3’], ‘test’)
print(dic6)