Skip to content
Related Articles

Related Articles

Count frequencies of all elements in array in Python using collections module
  • Difficulty Level : Easy
  • Last Updated : 19 Feb, 2021
GeeksforGeeks - Summer Carnival Banner

Given an unsorted array of n integers which can contains n integers. Count frequency of all elements that are present in array.
Examples:

Input : arr[] = [1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 4, 5, 5]
Output : 1 -> 4
         2 -> 4
         3 -> 2
         4 -> 1
         5 -> 2

This problem can be solved in many ways, refer Count frequencies of all elements in array link. In Python, we can quickly solve this problem in using Collections module.




# Function to count frequency of each element 
import collections
  
# it returns a dictionary data structure whose 
# keys are array elements and values are their 
# corresponding frequencies {1: 4, 2: 4, 3: 2, 
# 5: 2, 4: 1}
def CountFrequency(arr):
    return collections.Counter(arr)  
  
# Driver function
if __name__ == "__main__":
  
    arr = [1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 4, 5, 5]
    freq = CountFrequency(arr)
  
    # iterate dictionary named as freq to print
    # count of each element
    for (key, value) in freq.items():
        print (key, " -> ", value)

Output:

1 -> 4
2 -> 4
3 -> 2
4 -> 1
5 -> 2



Related Article :
Counting the frequencies in a list using dictionary in Python

This article is contributed by Shashank Mishra (Gullu). If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.

Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics.

To begin with, your interview preparations Enhance your Data Structures concepts with the Python DS Course.

My Personal Notes arrow_drop_up
Recommended Articles
Page :