Python – Multimode of List

Sometimes, while working with Python lists we can have a problem in which we need to find mode in list i.e most frequently occurring character. But sometimes, we can have more than 1 modes. This situation is called multimode. Lets discuss certain ways in which this task can be performed. 

Method #1 : Using loop + formula The simpler manner to approach this problem is to employ the formula for finding multimode and perform using loop shorthands. This is the most basic approach to solve this problem. 

Python3

# Python3 code to demonstrate working of
# Multimode of List
# using loop + formula
import math
from collections import Counter

# initialize list
test_list = [1, 2, 1, 2, 3, 4, 3]

# printing original list
print("The original list is : " + str(test_list))

# Multimode of List
# using loop + formula
res = []
test_list1 = Counter(test_list)
temp = test_list1.most_common(1)[0][1]
for ele in test_list:
  if test_list.count(ele) == temp:
    res.append(ele)
res = list(set(res))

# printing result
print("The multimode of list is : " + str(res))

Output : 

The original list is : [1, 2, 1, 2, 3, 4, 3]
The multimode of list is : [1, 2, 3]

Time Complexity: O(n*n) where n is the number of elements in the list “test_list”. 
Auxiliary Space: O(n) where n is the number of elements in the list “test_list”. 

Method #2 : Using statistics.multimode() This task can also be performed using inbuilt function of mulimode(). This is new in Python versions >= 3.8. 

Python3

# Python3 code to demonstrate working of
# Multimode of List
# using statistics.multimode()
import statistics

# initialize list
test_list = [1, 2, 1, 2, 3, 4, 3]

# printing original list
print("The original list is : " + str(test_list))

# Multimode of List
# using statistics.multimode()
res = statistics.multimode(test_list)

# printing result
print("The multimode of list is : " + str(res))

Output : 

The original list is : [1, 2, 1, 2, 3, 4, 3]
The multimode of list is : [1, 2, 3]

Time Complexity: O(n), where n is the number of elements in the list “test_list”.
Auxiliary Space: O(n), where n is the number of elements in the list “test_list”.