Python | Find the sum of the frequency of given items in a list



Example :

  Input:  list1 = [1, 2, 3] list2 = [2, 1, 2, 1, 3, 5, 2, 3]  Output:  7  Explanation:  No of time 1 occurring in list2 is: 2 No of time 2 occurring in list2 is: 3 No of time 3 occurring in list2 is: 2 Sum = 2 + 3 + 2 = 7 

Below are some ways to solve the above problems.

Method # 1: Using sum ()

# Python code for finding the sum of frequencies
# element of the first list in the second list.

 
# Initialization list

Input1 = [ 1 , 2 , 3 ]

Input2 = [ 2 , 1 , 2 , 1 , 3 , 5 , 2 , 3 ]

  
# Using sum

Output = sum (Input2.count (elem) for elem in  Input1)

 
# Printout

print ( "Initial list are:" , Input1, Input2)

print ( "Frequency is:" , Output)

Exit:

 Initial list are: [1, 2, 3] [2, 1, 2, 1, 3, 5, 2, 3] Frequency is: 7 

Method # 2: Using sum () and Counter()

from collections import Counter

 
# Init list andization

Input1 = [ 1 , 2 , 3 ]

Input2 = [ 2 , 1 , 2 , 1 , 3 , 5 , 2 , 3 ]

  

 

temp = < / code> Counter (Input2)

Output = sum (temp [x] for x in Input1)

  
# Printout

print ( " Initial list are: " , Input1, Input2)

print ( "Frequency is:" , Output)

Exit:

 Initial list are: [1, 2, 3] [2, 1, 2, 1, 3, 5, 2, 3] Frequency is: 7