Python：關於字典的相關操作

標籤：

>>> people = {"Tom":170, "Jack":175, "Kite":160, "White":180}    #定義一個字典
>>> for name in people:      #擷取value的值
 print people[name]

180
160
175
170
>>> for name in people:      #擷取key的值
 print name

White
Kite
Jack
Tom
>>> people.keys()           # 擷取所有key的值，和上面的for迴圈結果一樣
[‘White‘, ‘Kite‘, ‘Jack‘, ‘Tom‘]
>>> people.values()        # 擷取所有value的值，和上面的for迴圈結果一樣
[180, 160, 175, 170]
>>> people.has_key("White")       #判斷字典中是否存在該鍵
True
>>> people["Tom"]          #通過key去擷取value
170
>>> print [i for i in people if people.get(i) == 175]        #通過value去擷取key，一句代碼搞定
[‘Jack‘]
>>> print [i * 2 for i in people if people.get(i) == 175]      #讓輸出的值重複兩次
[‘JackJack‘]
>>> print [(i + " ") * 2 for i in people if people.get(i) == 175 ]      #給重複的結果中間插入空格
[‘Jack Jack ‘]
>>> def test():
 print [i for i in people if people.get(i) == 175]       #把該代碼定義成一個函數test()

 
>>> test()
[‘Jack‘]
>>> def test01(sg):                                             #把該代碼定義為有參的函數test01()
 print [i for i in people if people.get(i) == sg]

>>> test01(175)
[‘Jack‘]

Python：關於字典的相關操作