(九)字典

####1 字典的基本结构
# dict
# info = {
#     'k1':'v1',
#     'k2':'v2'
# }
####2 字典的value可以是任何值
# info = {
#     'k1':18,
#     'k2':True,
#     'k3':[
#         11,
#         22,
#         33,
#         {
#             'kk1':'vv1',
#             'kk2':'vv2',
#             'kk3':(11,22,'qsg')
#         }
#     ],
#     'k4':(11,22,33,44)
# }
# print(info)

####3 、列表、字典不能做字典的key值
# info = {
#     1:'ads',
#     'k1':'rwefd',
#     True:'123',
#     (11,22,33,):123,
#     [11,22,'abc']:345,
#     {'k1':'v1'}:1234
# }

####4 字典无序的。
# info = {
#     'k1':18,
#     'k2':True,
#     'k3':[
#         11,
#         22,
#         33,
#         {
#             'kk1':'vv1',
#             'kk2':'vv2',
#             'kk3':(11,22,'qsg')
#         }
#     ],
#     'k4':(11,22,33,44)
# }
# print(info)


####5 可以通过建key查找

# info = {
#     'k1':18,
#     2:True,
#     'k3':[
#         22,
#         33,
#         {
#             'kk1':'vv1',
#             'kk2':'vv2',
#             'kk3':(11,22,'qsg')
#         }
#     ],
#     'k4':(11,22,33,44)
# }
# v = info['k1']
# print(v)
# v = info[2]
# print(v)

# v = info['k3'][2]['kk3'][0]
# print(v)  #11

####6 字典支持del 删除
# info = {
#     'k1':18,
#     2:True,
#     'k3':[
#         22,
#         33,
#         {
#             'kk1':'vv1',
#             'kk2':'vv2',
#             'kk3':(11,22,'qsg')
#         }
#     ],
#     'k4':(11,22,33,44)
# }
# del info['k3'][2]['kk1']
# print(info)

####7 字典可以被for 循环
# info = {
#     'k1':18,
#     2:True,
#     'k3':[
#         22,
#         33,
#         {
#             'kk1':'vv1',
#             'kk2':'vv2',
#             'kk3':(11,22,'qsg')
#         }
#     ],
#     'k4':(11,22,33,44)
# }
#
# for k,v in info.items():
#     print(k,v)


#字典的方法
#1 dict    clear()

#2 copy   浅拷贝

##3 dict.formkeys()  根据序列，创建字典，并指定统一的值。
# v = dict.fromkeys(['k1','rrr',345],999)
# print(v)

#根据key获取值，key不存在时，可以指定值，默认值是None
# dic = {
#     'k1':'v1',
#     'k2':'v2'
# }
# v = dic['k11']  #当没有K11的key时会报错！
# print(v)
#4  get()#######
# v = dic.get('k11',999)  #当没有这个key时，可以指定
# print(v)

#5  ###dic.items()
# print(dic.items())  #dict_items([('k1', 'v1')])
#
#6 ####dic.keys()
# print(dic.keys())  #dict_keys(['k1'])

####7 pop、 popitem删除并获取值##
# v = dic.pop('k1')
# print(dic,v)

# v = dic.popitem()
# print(dic,v)

#8  设置值dic.setdefault
#已存在，不设置，获取当前key对应的值
#不存在，设置，获取当前key对应的值

# dic = {
#     'k1':'v1',
#     'k2':'v2'
# }
#
# v = dic.setdefault('k11',123)
# print(dic,v)


###9 update跟新字典########
# dic = {
#     'k1':'v1',
#     'k2':'v2'
# }
#(一)update的第一种写法直接写一个字典
# dic.update({'k1':'22222','k3':22222})
# print(dic)
#（二）update的第二种写法，k=v
# dic.update(k1=3333,k3=1111,k6='dwf')
# print(dic)


###value####
# dic.values()
# print(dic.values())

#####字典最常用的keys()、values()、items()、get()、update()#####