09 字典操作

dic = {
    'name':['一','二'],
    'py9':[{'num':71,'avg_age':18},
           {'num': 71, 'avg_age': 18},
           {'num': 71, 'avg_age': 18}
           ],
    True: 1,
    (1,2,3):'sdlfljsdf',
    2:'二哥'
}
print(dic)

#增加

dic1 = {'age':18,'name':'jin','sex':'male',}
dic1['hight'] = 185     #没有就增加
print(dic1)     #{'age': 18, 'name': 'jin', 'sex': 'male', 'hight': 185}
dic1['age'] = 16        #有就覆盖
print(dic1)     #{'age': 16, 'name': 'jin', 'sex': 'male', 'hight': 185}
dic1 = {'age':18,'name':'jin','sex':'male',}
dic1.setdefault('weight')   #没有就增加
print(dic1)     #{'age': 18, 'name': 'jin', 'sex': 'male', 'weight': None}
dic1 = {'age':18,'name':'jin','sex':'male',}
dic1.setdefault('weight',150)   #没有就增加
print(dic1)     #{'age': 18, 'name': 'jin', 'sex': 'male', 'weight': 150}
dic1 = {'age':18,'name':'jin','sex':'male',}
dic1.setdefault('name','大一')    #有不改变
print(dic1)     #{'age': 18, 'name': 'jin', 'sex': 'male'}

#删除

dic1 = {'age':18,'name':'jin','sex':'male',}
print(dic1.pop('age')) #有返回值 18，如果没有此键就会报错
print(dic1)     #{'name': 'jin', 'sex': 'male'}
dic1 = {'age':18,'name':'jin','sex':'male',}
print(dic1.pop('二哥',None)) #如果没有此键不报错
print(dic1.pop('二哥','没有此键')) #如果没有此键就显示"没有此键"，可油设置返回值
print(dic1)     #{'name': 'jin', 'sex': 'male'}

dic1 = {'age':18,'name':'jin','sex':'male',}
print(dic1.popitem())  #随机删除  返回一个元组('sex', 'male')
print(dic1)     #{'age': 18, 'name': 'jin'}
dic1.clear()    #清空字典
del dic1        #删除字典

#更改 更新

#更改  update
dic1 = {'age':18,'name':'jin','sex':'male',}
dic1['age'] = 16
print(dic1)     #{'age': 16, 'name': 'jin', 'sex': 'male'}
#更新
dic = {'name':'jin','age':18,'sex':'male'}
dic2 = {'name':'alex','weight':75}
dic2.update(dic)    #在dic2中，有与dic相同的就更新，没有就增加
print(dic2)     #{'name': 'jin', 'weight': 75, 'age': 18, 'sex': 'male'}

#查找

dic1 = {'age':18,'name':'jin','sex':'male',}
print(dic1.keys(),type(dic1.keys()))    #键dict_keys(['age', 'name', 'sex']) <class 'dict_keys'>
print(dic1.values())        #值dict_values([18, 'jin', 'male'])
print(dic1.items())         #dict_items([('age', 18), ('name', 'jin'), ('sex', 'male')])

for i in dic1:
    print(i)        #打印的键
# age
# name
# sex
for i in dic1.keys():
    print(i)        #打印的键(同上)
for i in dic1.values():
    print(i)        #打印的值
# 18
# jin
# male
for i in dic1.items():
    print(i)        #打印元组
# ('age', 18)
# ('name', 'jin')
# ('sex', 'male')
for i,j in dic1.items():
    print(i,j)        #打印
# age 18
# name jin
# sex male
print(dic1['name'])     #jin
print(dic1.get('name1'))    #None
print(dic1.get('name1','没有这个键'))    #没有这个键

#知识点：

a = 1
b = 2
a,b = b,a
print(a,b)      #2 1
a,b = [1,2]
print(a,b)      #1 2
a,b = [1,2],[3,4,5]
print(a,b)      #[1, 2] [3, 4, 5]
a,b = (1,2)
print(a,b)      #1 2