Python – Test if element is part of dictionary

Given a dictionary, test if K is part of keys or values of dictionary.

Input : test_dict = {“Gfg” : 1, “is” : 3, “Best” : 2}, K = “Best”
Output : True
Explanation : “Best” is present in Dictionary as Key.

Input : test_dict = {“Gfg” : 1, “is” : 3, “Best” : 2}, K = “Geeks”
Output : False
Explanation : “Geeks” is not present in Dictionary as Key.

Method #1 : Using any() + items() + generator expression 

The combination of above functions can be used to solve this problem. In this, we check for any element using any() and items() is used to extract all the keys and values of dictionary.

Python3

# Python3 code to demonstrate working of
# Test if element is part of dictionary
# Using any() + generator expression + items()

# initializing dictionary
test_dict = {"Gfg" : 1, "is" :  3, "Best" : 2}

# printing original dictionary
print("The original dictionary is : " + str(test_dict))

# initializing K
K = "Gfg"

# using any() to check for both keys and values
res = any(K == key or K == val for key, val in test_dict.items())

# printing result
print("Is K present in dictionary? : " + str(res))

Output

The original dictionary is : {'Gfg': 1, 'is': 3, 'Best': 2}
Is K present in dictionary? : True

Method #2 : Using chain.from_iterables() + items()

The combination of above functions can be used to solve this problem. In this, we flatten all the items and then check if K is present is any of the items().

Python3

# Python3 code to demonstrate working of
# Test if element is part of dictionary
# Using chain.from_iterables() + items()
from itertools import chain

# initializing dictionary
test_dict = {"Gfg" : 1, "is" :  3, "Best" : 2}

# printing original dictionary
print("The original dictionary is : " + str(test_dict))

# initializing K
K = "Gfg"

# flattening key-values and then checking
# using in operator
res = K in chain.from_iterable(test_dict.items())

# printing result
print("Is K present in dictionary? : " + str(res))

Output

The original dictionary is : {'Gfg': 1, 'is': 3, 'Best': 2}
Is K present in dictionary? : True