python基礎(chǔ)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(chǔ)知識之字典(Dict)的相關(guān)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(jù)結(jié)構(gòu)，字典的數(shù)據(jù)是用“{ }”裝的（列表：[ ]，元組：( )），字典的元素是一一對應的關(guān)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(jù)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(lǐng)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(nèi)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(guān)于python基礎(chǔ)知識之字典(Dict)的文章就介紹到這了,更多相關(guān)python 字典 Dict內(nèi)容請搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家！
您可能感興趣的文章:
- Python 字典(Dictionary)操作詳解
- python兩種遍歷字典(dict)的方法比較
- python通過字典dict判斷指定鍵值是否存在的方法
- python 將字符串轉(zhuǎn)換成字典dict的各種方式總結(jié)
- Python中字典（dict）合并的四種方法總結(jié)
- Python的“二維”字典 (two-dimension dictionary)定義與實現(xiàn)方法
- Python中字典(dict)和列表(list)的排序方法實例
- python 將字符串轉(zhuǎn)換成字典dict
- python 字典(dict)按鍵和值排序
- Python中實現(xiàn)兩個字典（dict）合并的方法
相關(guān)文章
這篇文章主要介紹了python實現(xiàn)將list拼接為一個字符串方式，具有很好的參考價值，希望對大家有所幫助。如有錯誤或未考慮完全的地方，望不吝賜教2022-11-11
基于Python實現(xiàn)將列表數(shù)據(jù)生成折線圖
這篇文章主要介紹了如何利用Python中的pandas庫和matplotlib庫，實現(xiàn)將列表數(shù)據(jù)生成折線圖，文中的示例代碼簡潔易懂，需要的可以參考一下2022-03-03
Python內(nèi)置函數(shù)input()示例詳解
input()函數(shù)是Python中用于獲取用戶輸入的一個簡單而強大的工具,它在創(chuàng)建需要用戶交互的程序時非常有用,這篇文章主要介紹了Python內(nèi)置函數(shù)input()詳解,需要的朋友可以參考下2024-04-04
Gradio中的button組件用于實現(xiàn)點擊事件,通過click事件綁定函數(shù)來處理值的變化,點擊時,函數(shù)接收組件的值作為輸入,返回新的值或更新組件的屬性,示例代碼展示了如何在點擊按鈕時修改文本框的值并控制按鈕的可見性2024-11-11
Jupyter notebook之如何快速打開ipynb文件
這篇文章主要介紹了Jupyter notebook之如何快速打開ipynb文件問題,具有很好的參考價值,希望對大家有所幫助,如有錯誤或未考慮完全的地方,望不吝賜教2023-09-09
Python基礎(chǔ)教程之tcp socket編程詳解及簡單實例
這篇文章主要介紹了Python基礎(chǔ)教程之tcp socket編程詳解及簡單實例的相關(guān)資料,需要的朋友可以參考下2017-02-02
今天小編就為大家分享一篇django url到views參數(shù)傳遞的實例，具有很好的參考價值，希望對大家有所幫助。一起跟隨小編過來看看吧2019-07-07
今天小編就為大家分享一篇selenium+python 對輸入框的輸入處理方法，具有很好的參考價值，希望對大家有所幫助。一起跟隨小編過來看看吧2018-10-10
3個Python?SQLAlchemy數(shù)據(jù)庫操作功能詳解
Python?SQLAlchemy?是一個強大且多功能的?Python?SQL?工具包和對象關(guān)系映射?(ORM)?系統(tǒng),提供了一整套眾所周知的企業(yè)級持久性模式,本文為大家整理了它必須了解的3個數(shù)據(jù)庫操作功能,希望對大家有所幫助2023-09-09
使用Pytorch訓練two-head網(wǎng)絡(luò)的操作
這篇文章主要介紹了使用Pytorch訓練two-head網(wǎng)絡(luò)的操作，具有很好的參考價值，希望對大家有所幫助。如有錯誤或未考慮完全的地方，望不吝賜教2021-05-05