Python3實現的字典遍曆操作詳解

這篇文章主要介紹了Python3實現的字典遍曆操作,結合執行個體形式分析了Python3針對字典鍵、索引值及索引值對遍曆的相關操作技巧,需要的朋友可以參考下

本文執行個體講述了Python3字典遍曆操作。分享給大家供大家參考，具體如下：

字典是針對非序列集合而提供的一種資料類型。

通過任意鍵尋找集合中值資訊的過程叫映射，python通過字典實現映射。

為字典賦值：

>>> d={'list':[1, 2, 3],1:123,'111':'python3','tuple':(4, 5, 6)}>>> print(d){1: 123, 'list': [1, 2, 3], '111': 'python3', 'tuple': (4, 5, 6)}

以上語句說明，字典中各項的順序與賦值時的順序可能不一致，即字典是無序的。

字典的遍曆有一下幾種：

1. 遍曆字典的鍵key

①

>>> d={'list':[1, 2, 3],1:123,'111':'python3','tuple':(4, 5, 6)}>>> for key in d:    print(str(key)+':'+str(d[key]))list:[1, 2, 3]1:123111:python3tuple:(4, 5, 6)

②

>>> d={'list':[1, 2, 3],1:123,'111':'python3','tuple':(4, 5, 6)}>>> for key in d.keys():    print(key)1list111tuple

2. 遍曆字典的值value

>>> d={'list':[1, 2, 3],1:123,'111':'python3','tuple':(4, 5, 6)}>>> for value in d.values():    print (value)[1, 2, 3]123python3(4, 5, 6)

3. 遍曆字典的項

>>> d={'list':[1, 2, 3],1:123,'111':'python3','tuple':(4, 5, 6)}>>> for item in d.items():    print(item)('list', [1, 2, 3])(1, 123)('111', 'python3')('tuple', (4, 5, 6))

4. 遍曆字典的key-value

①

>>> d={'list':[1, 2, 3],1:123,'111':'python3','tuple':(4, 5, 6)}>>> for key,value in d.items():    print(key,value)list [1, 2, 3]1 123111 python3tuple (4, 5, 6)

②

>>> d={'list':[1, 2, 3],1:123,'111':'python3','tuple':(4, 5, 6)}>>> for (key,value) in d.items():    print(key,value)list [1, 2, 3]1 123111 python3tuple (4, 5, 6)

上述樣本運行效果如所示：