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Counting the frequencies in a list using dictionary in Python
In this article we develop a program to calculate the frequency of each element present in a list.
Using a dictionary
Here we capture the items as the keys of a dictionary and their frequencies as the values.
Example
list = ['a','b','a','c','d','c','c'] frequency = {} for item in list: if (item in frequency): frequency[item] += 1 else: frequency[item] = 1 for key, value in frequency.items(): print("% s -> % d" % (key, value))
Output
Running the above code gives us the following result −
a -> 2 b -> 1 c -> 3 d -> 1
Using count()
Here we use the in-built count() function to count the number of occurrences of an item in the list.
Output
list = ['a','b','a','c','d','c','c'] frequency = {} for item in list: frequency[item] = list.count(item) for key, value in frequency.items(): print("% s -> % d" % (key, value))
Running the above code gives us the following result >
a -> 2 b -> 1 c -> 3 d -> 1
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