python學習第七篇——字典訪問鍵與值

此程序的目的在於，正確而簡單的訪問字典的鍵與值

favorite_languages={
    'jen':['python','c'],
    'sarah':['c'],
    'edward':['ruby','go'],
    'phil':['python','java'],
    }
 #古老的方法訪問字典中鍵與值
for element in favorite_languages:
    print(element +"'s favorite languages are:")
    print("\t"+str(favorite_languages[element]))
# 正確的方法訪問鍵與值
for name,languages in favorite_languages.items():
    print("\n"+name.title()+"'s favorite languages are:")
    for language in languages:
        print("\t"+language.title())

for name,languages in favorite_languages.items():
    if len(languages) == 1:
        print("\n"+name.title()+"'s favorite languages is:")
    else:
        print("\n"+name.title()+"'s favorite languages are:")
    for language in languages:
        print("\t"+language.title())

1  代碼中12-15行代碼是正確而又簡便的訪問字典鍵與值的方式。注意for 后面可以跟兩個變量，一個用來訪問鍵，一個用來訪問值。

2 .item()類可以方便的完成這種訪問，實際上.item（）返回了兩個列表,一個給了name,另一個給了languages.

3  注意第二個for循環的位置