Python | Test if key exists in tuple keys dictionary

Last Updated : 21 Nov, 2019

Sometimes, while working with dictionary data, we need to check if a particular key is present in dictionary. If keys are elementary, the solution of problem in discussed and easier to solve. But sometimes, we can have tuple as key of dictionary. Let’s discuss certain ways in which this task can be performed.

Method #1 : Using any() + generator expression

Combination of above functionalities can be used to perform this task. In this, we check for each element inside each key for the target key. The any() is used to check in any keys of dictionary.

# Python3 code to demonstrate working of
# Test if key exists in tuple keys dictionary
# using any() + generator expression
  
# initialize dictionary
test_dict = {(4, 5) : '1', (8, 9) : '2', (10, 11) : '3'}
  
# printing original dictionary
print("The original dictionary : " + str(test_dict))
  
# Test key 
key = 10
  
# Test if key exists in tuple keys dictionary
# using any() + generator expression
res = any(key in sub for sub in test_dict)
  
# printing result
print("Does key exists in dictionary? : " + str(res))

Output :

The original dictionary : {(4, 5): '1', (8, 9): '2', (10, 11): '3'}
Does key exists in dictionary? : True

Method #2 : Using from_iterable()

This task can also be performed using this function. In this, we flatten the keys and then check for existence.

# Python3 code to demonstrate working of
# Test if key exists in tuple keys dictionary
# using from_iterable()
from itertools import chain
  
# initialize dictionary
test_dict = {(4, 5) : '1', (8, 9) : '2', (10, 11) : '3'}
  
# printing original dictionary
print("The original dictionary : " + str(test_dict))
  
# Test key 
key = 10
  
# Test if key exists in tuple keys dictionary
# using from_iterable()
res = key in chain.from_iterable(test_dict)
  
# printing result
print("Does key exists in dictionary? : " + str(res))

Output :

The original dictionary : {(4, 5): '1', (8, 9): '2', (10, 11): '3'}
Does key exists in dictionary? : True

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