五 字典

# ======================================基本使用======================================

# 1、用途：

# 2、定义方式：在{}内用逗号分割开多个元素，每个元素都是key:value的形式

#             其中value可以是任意类型，而key必须是不可变类型，通常是字符串类型

# dic = {1:111111,33.33:"aaa",(1,2,3):'bbbb'}  # dic =  dict(...)

# print(dic[(1,2,3)])

# dict数据类型转换

# dic = dict([('name','egon'),('age',18)])

# print(dic)

#

# dic = dict(name='egon',age=18,gender='male')

# print(dic)

# 3、常用操作+内置的方法

# 优先掌握的操作：

# 1、按key存取值：可存可取

# dic = {'name': 'egon', 'age': 18}

# print(dic['name'])

# print(dic['name1'])  # 直接报错

# print(dic.get('name'))

# print(dic.get('name1'))  # none

# dic['gender'] = 'male'

# print(dic)  # # {'name': 'egon', 'age ': 18, 'gender': 'male'}

# dic = {'name': 'egon', 'age': 18,'name':"tom",'name':'lili'}

# print(dic)  #{'name': 'lili', 'age': 18}

# 2、长度len

# dic = {'name': 'egon', 'age': 18}

# print(len(dic))  # 2

# 3、成员运算in和not in

# dic = {'name': 'egon', 'age': 18}

# print('name' in dic)

# 4、删除

# 万能删除

# del dic['name']

# print(dic)

# dic.pop()

# v = dic.pop('name')

# print(v)  # egon

# dic.popitem()

# res = dic.popitem()

# print(res)  # ('age', 18)

# 5、键keys()，值values()，键值对items()

"""

>>> dic = {'name': 'egon', 'age': 18}

>>>

>>>

>>> dic.keys()

['age', 'name']

>>>

>>> dic.values()

[18, 'egon']

>>>

>>> dic.items()

[('age', 18), ('name', 'egon')]

"""

# 6、循环

# dic = {'name': 'egon', 'age': 18}

# # for k in dic.keys():

# #     print(k)

#

# # for k in dic:

# #     print(k)  # name age

#

# # for v in dic.values():

# #     print(v)  # egon 18

#

# for k,v in dic.items():

#     print(k,v)  # name egon    age 18

# 需要掌握的操作

# dic = {'name': 'egon', 'age': 18}

# dic.update({'name': "EGON", 'gender': "male"})

# print(dic)

# dic = {'name': 'egon', 'age': 18,'level':100}

# # 如果level这个key存在于字典中，则什么都不做

# # 否则就往字典中添加一组键值对'level':10

#

# # if 'level' in dic:

# #     pass

# # else:

# #     dic['level'] = 10

#

# v = dic.setdefault('level',10)  # 存在则不变 不存在则新建

# # print(dic)  # {'name': 'egon', 'age': 18, 'level': 10}

# print(v)  # 10

​

# dic = {'name': 'egon', 'age': 18,'level':22}

# v = dic.setdefault('level',10)

# print(dic)  # {'name': 'egon', 'age': 18, 'level': 22}

# print(v)  # 22

# l = ['name', 'age', 'gender']

# dic = {}

# for x in l:

#     dic[x] = None

# dic = {}.fromkeys(l,None)  # {'name': None, 'age': None, 'gender': None}

# dic = {}.fromkeys(l,[])  # {'name': [], 'age': [], 'gender': []}

# dic['name'].append(111)  # {'name': [111], 'age': [111], 'gender': [111]}

# print(dic)

# 练习：

nums = [11, 22, 33, 44, 55, 66, 77, 88, 99, 90]

dic = {'k1': [], 'k2': []}

for num in nums:

    if num > 66:

        dic['k2'].append(num)

    else:

        dic['k1'].append(num)

print(dic)  # {'k1': [11, 22, 33, 44, 55, 66], 'k2': [77, 88, 99, 90]}

# ======================================该类型总结====================================

# 存多个值

# 无序

# 可变