python基礎知識之字典(Dict)
更新時間：2023年02月19日 09:36:26 作者：51碼銀
這篇文章主要介紹了python基礎知識之字典(Dict)的相關資料,需要的朋友可以參考下
一、字典的基本操作
1.定義字典
字典也是一個列表型的數(shù)據結構，字典的數(shù)據是用“{ }”裝的（列表：[ ]，元組：( )），字典的元素是一一對應的關系“key-value”。
格式：
Dictname={ key1:value1,...,key2:value2}
#value是任何的python的對象
#字典的元素數(shù)量也是用len()函數(shù)
多說無益，直接看例子比較清晰：
實例：
flower={'rose':10,'orchid':16,'carnation':8}
tea={'紅茶':30,'綠茶':20,'茉莉花茶':40}
print(flower)
print(tea)
print("字典flower的元素數(shù)量是：",len(flower))
print("字典的數(shù)據類型：",type(tea))
2.建立空字典
實例：
print("``````````````````````````````````````````````````````````")
flower={}
flower['rose']=13
flower['orchid']=16
print(flower)
print("``````````````````````````````````````````````````````````")
3.列出字典元素的值
格式：
flower【'rose'】
#注意列出字典元素的值要用中括號哦“[ ]”
#上面語句表達的意思是字典 flower 的 rose（key）的對應 10（value）值。
實例：
print("``````````````````````````````````````````````````````````")
flower={'rose':10,'orchid':16,'carnation':8}
tea={'紅茶':30,'綠茶':20,'茉莉花茶':40}
print("一支玫瑰的價錢是：",flower['rose'])
print("紅茶一袋的價錢是：",tea['紅茶'])
print("``````````````````````````````````````````````````````````")
如果有兩個“rose”，兩個“紅茶”呢，元素對應的值（value）是哪個呢？
print("``````````````````````````````````````````````````````````")
flower={'rose':10,'orchid':16,'carnation':8,'rose':15}
tea={'紅茶':30,'綠茶':20,'茉莉花茶':40,'紅茶':13}
print("一支玫瑰的價錢是：",flower['rose'])
print("紅茶一袋的價錢是：",tea['紅茶'])
print("``````````````````````````````````````````````````````````")
如上所示，字典中的元素對應值被后面的值占領了。
4.增加字典元素
實例：
print("``````````````````````````````````````````````````````````")
flower={'rose':10,'orchid':16,'carnation':8}
tea={'紅茶':30,'綠茶':20,'茉莉花茶':40}
flower['tuilp']=13
print(flower)
print("``````````````````````````````````````````````````````````")
5.更改元素內容
實例：
print("``````````````````````````````````````````````````````````")
flower={'rose':10,'orchid':16,'carnation':8}
tea={'紅茶':30,'綠茶':20,'茉莉花茶':40}
flower['rose']=13
print(flower)
print("``````````````````````````````````````````````````````````")
6.刪除字典（特定元素）
刪除元素實例：
print("``````````````````````````````````````````````````````````")
flower={'rose':10,'orchid':16,'carnation':8}
tea={'紅茶':30,'綠茶':20,'茉莉花茶':40}
del flower['rose']
print(flower)
print("``````````````````````````````````````````````````````````")
刪除字典實例：
print("``````````````````````````````````````````````````````````")
flower={'rose':10,'orchid':16,'carnation':8}
del flower
print(flower)
print("``````````````````````````````````````````````````````````")
7. 字典的復制
print("``````````````````````````````````````````````````````````")
flower={'rose':10,'orchid':16,'carnation':8}
copyflower=flower.copy()
print(flower)
print(copyflower)
print("``````````````````````````````````````````````````````````")
二、遍歷字典
1.遍歷字典的key-value
flower={'rose':10,
'orchid':16,
'carnation':8}
for flowers,price in flower.items():
print("花名：",flowers)
print("價格：",price)
print("\n")
2.遍歷字典的鍵(key)
flower={'rose':10,
'orchid':16,
'carnation':8}
for flowers in flower.keys():
print("花名：",flowers)
print("\n")
沒有keys()函數(shù)也行：
flower={'rose':10,
'orchid':16,
'carnation':8}
for flowers in flower:
print("花名：",flowers)
3.遍歷字典的值（value）
flower={'rose':10,
'orchid':16,
'carnation':8}
for flowers in flower.values():
print("價格：",flowers)
4.字典里面放字典
實例：人物介紹
role={
'魯班':{
'技能':'土木建筑',
'職業(yè)':'工匠'
},
'鐘無艷':{
'技能':'出謀劃策',
'職業(yè)':'中國古代四大丑女之一'
},
'蔡文姬':{
'技能':'琴棋書畫',
'職業(yè)':'董祀之妻'
}
}
for a,b in role.items():
print("姓名：",a)
print("介紹：",b)
三、簡單介紹下函數(shù)
len()：求元素個數(shù)
get()：搜尋字典的key
格式：返回值=字典名.get('key')
pop()：刪除元素
格式：返回值=字典名.pop('key')
到此這篇關于python基礎知識之字典(Dict)的文章就介紹到這了,更多相關python 字典 Dict內容請搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關文章希望大家以后多多支持腳本之家！
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