Python：如何迭代兩個以上的詞典？

Question

不太確定我在這里做錯了什么。 我以為zip方法可以檢查一個值是否在多個列表中？ 我希望它執行的操作是檢查該值是否在那些詞典中的任何一個中，如果是，則打印其鍵，但如果不是，則僅打印一個字符串（“不在任何詞典中”）。 此方法出於某些原因會用實際字典打印其中的40個。

MLB_Teams = {1: 'New York Yankees', 2: 'Pittsburgh Pirates'}
NBA_Teams = {1: 'Houston Rockets', 2: 'Brooklyn Nets'}
NFL_Teams = {1: 'Philadelphia Eagles', 2: 'Detroit Lions'}

for (key,value), (key,value), (key, value) in zip(MLB_Teams.items(), NBA_Teams.items(), NFL_Teams.items()):
    reply = 'Houston Rockets'
    if reply == value:
        print(key)
    else:
        print('Not In Any Dictionary')

Answer 1

我認為您可以通過一種非常簡單的方式做到這一點：

MLB_Teams = {1: 'New York Yankees', 2: 'Pittsburgh Pirates'}
NBA_Teams = {1: 'Houston Rockets', 2: 'Brooklyn Nets'}
NFL_Teams = {1: 'Philadelphia Eagles', 2: 'Detroit Lions'}

v = 'Philadelphia Eagles'

def find_in_dict(val, d):
    for k, v in d.items():
        if v == val:
            print(k)
            return True

for dd in (MLB_Teams, NBA_Teams, NFL_Teams):
    if find_in_dict(v, dd):
        break
else:
    print('Not In Any Dictionary')

Answer 2

問題在於您如何將變量名重用於鍵和值。 添加打印語句以查看效果。

for (key,value), (key,value), (key, value) in zip(MLB_Teams.items(), NBA_Teams.items(), NFL_Teams.items()):
    print(value) #added
    reply = 'Houston Rockets'
    if reply == value:
        print(key)
    else:
        print('Not In Any Dictionary')
#output
Philadelphia Eagles
Not In Any Dictionary
Detroit Lions
Not In Any Dictionary

變量key和value重新分配給元組中的最后一個條目。

如果稍后再處理包裝，則可以使用zip。

MLB_Teams = {1: 'New York Yankees', 2: 'Pittsburgh Pirates'}
NBA_Teams = {1: 'Houston Rockets', 2: 'Brooklyn Nets'}
NFL_Teams = {1: 'Philadelphia Eagles', 2: 'Detroit Lions'}
reply = 'Houston Rockets'
for tups in zip(MLB_Teams.items(), NBA_Teams.items(), NFL_Teams.items()):
    if any(reply == val for key,val in tups):
        print(tups[0][0]) #key
    else:
        print('Not In Any Dictionary')

#output
1
Not In Any Dictionary