Python：如何迭代两个以上的词典？

Question

Not really sure what I'm doing wrong here. I thought the zip method would work to check if a value is in multiple lists? What I'd want it to do is check to see if that value is in any of those dictionaries, and if so, to print its key, but if not, then print only one string of ('Not in Any Dictionary'). This method prints 40 of them for some reason with the real dictionaries.

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

I think you can do it in a very simple way:

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

The issue lies in how you've reused the variable names for key and value. Add a print statement to see the effect.

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

The variables key and value get reassigned to the last entry in the tuple.

You can use the zip just fine if you handle unpacking later.

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