Python初学——字典

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字典：

键——值对应

dictory={
    'color':'green',
    'score':5,
    'color2':'yellow'
    }

1、添加与删减：

dictory['color1']='red'
dictory['color3']='white'
print(dictory)
del dictory['score']
print(dictory)
·································

{‘color’: ‘green’, ‘score’: 5, ‘color2’: ‘yellow’, ‘color1’: ‘red’, ‘color3’: ‘white’}
{‘color’: ‘green’, ‘color2’: ‘yellow’, ‘color1’: ‘red’, ‘color3’: ‘white’}

2、遍历：

遍历所有的键与值：
for key,value in dictory.items():
    print('\n'+key)
    print(value)
只遍历键：采用keys()方法

for key in dictory.keys():
    print(key)
······························

color
color2
color1
color3

只遍历值：采用value()方法：

for value in dictory.values():
    print(value)
······························

green
yellow
red
white

3、字典的嵌套：

我们可以将列表存储在字典中

pizza={
    'crust':'thick',
    'top':['mushroom','cheese']
}
print("You ordered a"+pizza['crust']+"-crust pizza"+"with the following top:")
for top in pizza['top']:
    print("\t"+top)
·····································

You ordered athick-crust pizzawith the following top:
mushroom
cheese

也可以在字典中存储字典：

用户组有两个用户，每个用户分别有一个字典包含他们的个人信息

users={
    'aestin':{
        'first':'albert',
        'second':'einst',
        'location':'pronceton'
    },
    'mcurin':{
        'first': 'maric',
        'second': 'scare',
        'location': 'paris'
    }
}
for username,user_info in users.items():
    print("\nusername:"+username)
    full_name=user_info['first']+" "+user_info['second']
    location=user_info['location']
    print("\tFull name:"+full_name.title())
    print("\tLocation:"+location.title())

 ·········································································

username:aestin
Full name:Albert Einst
Location:Pronceton

username:mcurin
Full name:Maric Scare
Location:Paris