Python most_common() Function

Python Counter | Majority Element

Last Updated : 24 May, 2022

Majority Element: A majority element in an array A[] of size n is an element that appears more than n/2 times (and hence there is at most one such element). Write a function which takes an array and emits the majority element (if it exists), otherwise prints NONE as follows: Examples:

Input : 3 3 4 2 4 4 2 4 4
Output : 4 

Input : 3 3 4 2 4 4 2 4
Output : NONE

We have existing solution for this problem please refer Majority Element link. We can solve this problem quickly in Python using Counter(iterable) function. Approach is simple,

Convert given list of elements into dictionary using Counter() method, having elements as keys and their frequencies as value.
Now traverse complete dictionary and check for element whose frequency follows the condition greater than (n/2) where n is size of list. That element will be majority element.

Python3

# Function to find majority element
from collections import Counter

def majority(arr):

    # convert array into dictionary
    freqDict = Counter(arr)

    # traverse dictionary and check majority element
    size = len(arr)
    for (key,val) in freqDict.items():
         if (val > (size/2)):
             print(key)
             return
    print('None')

# Driver program
if __name__ == "__main__":
    arr = [3,3,4,2,4,4,2,4,4] 
    majority(arr)

Output:

Python most_common() Function

S

Shashank Mishra

Improve

Article Tags :

Practice Tags :

Similar Reads

Python | Counter Objects | elements()

Counter class is a special type of object data-set provided with the collections module in Python3. Collections module provides the user with specialized container datatypes, thus, providing an alternative to Python's general-purpose built-ins like dictionaries, lists, and tuples. Counter is a sub-c

Python - Find all elements count in list

In Python, counting the occurrences of all elements in a list is to determine how many times each unique element appears in the list. In this article, we will explore different methods to achieve this. The collections.Counter class is specifically designed for counting hashable objects. It provides

Python List count() method

The count() method is used to find the number of times a specific element occurs in a list. It is very useful in scenarios where we need to perform frequency analysis on the data.Let's look at a basic example of the count() method.Pythona = [1, 2, 3, 1, 2, 1, 4] c = a.count(1) print(c)Output3 Explan

Numpy count_nonzero method | Python

numpy.count_nonzero() function counts the number of non-zero values in the array arr. Syntax : numpy.count_nonzero(arr, axis=None) Parameters : arr : [array_like] The array for which to count non-zeros. axis : [int or tuple, optional] Axis or tuple of axes along which to count non-zeros. Default is

Python most_common() Function

most_common() function is a method provided by the Counter class in Python's collections module. It returns a list of the n most common elements and their counts from a collection, sorted by frequency. Example:Pythonfrom collections import Counter a = ['apple', 'banana', 'apple', 'orange', 'banana',

Python | Count occurrences of an element in a Tuple

In this program, we need to accept a tuple and then find the number of times an item is present in the tuple. This can be done in various ways, but in this article, we will see how this can be done using a simple approach and how inbuilt functions can be used to solve this problem. Examples: Tuple:

Check if element exists in list in Python

In this article, we will explore various methods to check if element exists in list in Python. The simplest way to check for the presence of an element in a list is using the in Keyword. Example:Pythona = [10, 20, 30, 40, 50] # Check if 30 exists in the list if 30 in a: print("Element exists in the

Mahotas - Majority filter

In this article, we will see how we can apply majority filter to the image in mahotas. In Majority filters for each group of pixels considered in the input map, a majority filter assign the predominant (=mostly frequently occurring) value or class name of these to the center pixel in the output map.

Count occurrences of an element in a list in Python

A common task when working with lists is to count how many times a specific element appears. In Python, we have several ways to count occurrences of an element using both built-in and custom methods.The simplest and most straightforward way to count occurrences of an element in a list is by using th

Python | sympy.divisor_count() method

With the help of sympy.divisor_count() method, we can count the number of divisors of the given integer. Syntax: divisor_count(n, modulus=1) Parameter: n - It denotes an integer. modulus - It is set to 1 by default. If modulus is not 1 then only those that are divisible by modulus are counted. Retur