字典 dict

dic = {
    'name':['大猛','小孟'],
    'py9':[{'num':71,'avg_age':18,},
           {'num': 71, 'avg_age': 18, },
           {'num': 71, 'avg_age': 18, },
           ],
    True:1,
    (1,2,3):'wuyiyi',
    2:'二哥',
}
print(dic)
dic1 = {'age': 18, 'name': 'jin', 'sex': 'male',}
#增：
dic1['high'] = 185  #没有键值对，添加
dic1['age'] = 16  #如果有键，则值覆盖

dic1.setdefault('weight')  # 有键值对，不做任何改变，没有才添加。
dic1.setdefault('weight',150)
dic1.setdefault('name','二哥')
print(dic1)

#删
print(dic1.pop('age'))   # 有返回值，按键去删除
print(dic1.pop('二哥',None))   # 可设置返回值
print(dic1)

print(dic1.popitem())  # 随机删除 有返回值 元组里面是删除的键值。
# print(dic1)

del dic1['name1']
print(dic1)
del dic1
print(dic1)

dic1.clear() #清空字典

#改  update
dic1['age'] = 16

dic = {"name":"jin","age":18,"sex":"male"}
dic2 = {"name":"alex","weight":75}
dic2.update(dic)  #

print(dic)
print(dic2)
dic1 = {'age': 18, 'name': 'jin', 'sex': 'male',}
#查
print(dic1.keys(),type(dic1.keys()))
print(dic1.values())
print(dic1.items())

for i in dic1:
    print(i)
for i in dic1.keys():
    print(i)

for i in dic1.values():
    print(i)

a,b = 1,2
print(a,b)

a = 1
b = 2
a,b = b,a
print(a,b)
a,b = [1,2],[2,3]
a,b = (1,2)
print(a,b)

for k,v in dic1.items():
    print(k,v)

v1 = dic1['name']
print(v1)

v2 = dic1['name1']  # 报错
print(v2)

print(dic1.get('name1','没有这个键'))