Python: 如何遍历超过 2 个字典？

Question

不太确定我做错了什么。我认为 zip 方法可以检查一个值是否在多个列表中？我想要它做的是检查该值是否在这些词典中的任何一个中，如果是，则打印其键，但如果不是，则仅打印一个字符串 ('Not in Any Dictionary')。由于某种原因，此方法使用真实词典打印了其中的 40 个。

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

我认为你可以用一种非常简单的方式做到这一点：

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

问题在于您如何重复使用键和值的变量名称。添加打印语句，看看效果。

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

变量键和值被重新分配给元组中的最后一个条目。

如果你稍后处理解包，你可以使用 zip 就好了。

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

Python: 如何遍历超过 2 个字典？

Python: How do I iterate over more than 2 dictionaries?

python

dictionary

iterator

for-loop

python-3.x