Python | Count keys with particular value in dictionary
Sometimes, while working with Python dictionaries, we can come across a problem in which we have a particular value, and we need to find frequency if it’s occurrence. Let’s discuss certain ways in which this problem can be solved.
Method #1 : Using loop
This problem can be solved using naive method of loop. In this we just iterate through each key in dictionary and when a match is found, the counter is increased.
# Python3 code to demonstrate working of# Count keys with particular value in dictionary# Using loop # Initialize dictionarytest_dict = {'gfg' : 1, 'is' : 2, 'best' : 3, 'for' : 2, 'CS' : 2} # printing original dictionaryprint("The original dictionary : " + str(test_dict)) # Initialize value K = 2 # Using loop# Selective key values in dictionaryres = 0for key in test_dict: if test_dict[key] == K: res = res + 1 # printing result print("Frequency of K is : " + str(res)) |
The original dictionary : {‘gfg’: 1, ‘CS’: 2, ‘best’: 3, ‘for’: 2, ‘is’: 2}
Frequency of K is : 3
Method #2 : Using sum() + values()
This can also be solved using the combination of sum() and value(). In this, sum is used to perform the summation of values filtered and values of dictionary are extracted using values()
# Python3 code to demonstrate working of# Count keys with particular value in dictionary# Using sum() + values() # Initialize dictionarytest_dict = {'gfg' : 1, 'is' : 2, 'best' : 3, 'for' : 2, 'CS' : 2} # printing original dictionaryprint("The original dictionary : " + str(test_dict)) # Initialize value K = 2 # Using sum() + values()# Selective key values in dictionaryres = sum(x == K for x in test_dict.values()) # printing result print("Frequency of K is : " + str(res)) |
The original dictionary : {‘gfg’: 1, ‘CS’: 2, ‘best’: 3, ‘for’: 2, ‘is’: 2}
Frequency of K is : 3
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