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Python program to print perfect numbers from the given list of integers

Printing perfect numbers: Here, we are going to learn how to find and print the perfect numbers from a given list in Python?
Submitted by Ankit Rai, on July 26, 2019

Given a list of the integer numbers and we have to print all perfect numbers present in the given list.

This Program iterating through each number one by one in the list, and check whether a given number is a perfect number or not. If a perfect number is found then print it else skip it.

In this program, checkPerfectNum() function is used to find its all positive divisors excluding that number and sum it all and then check for perfect number condition.

Explanation: For Example, 28 is a perfect number since divisors of 28 are 1, 2, 4,7,14 then sum of its divisor is 1 + 2 + 4 + 7 + 14 = 28.

Note: A perfect number is a positive integer that is equal to the sum of its proper positive divisors.

Python code to print perfect numbers from the given list of integers

# Define a function for checking perfect number
# and print that number
def checkPerfectNum(n) :
	# initialisation 
	i = 2;sum = 1;

	# iterating till n//2 value
	while(i <= n//2 ) :
		# if proper divisor then add it.
		if (n % i == 0) :
			sum += i			
		
		# incrementing i by one
		i += 1
		
		# check sum equal to n or not
		if sum == n :
			print(n,end=' ')

# Main code
if __name__ == "__main__" :

	# take list of number as an input from user 
	# and typecast into integer
	print("Enter list of integers: ")
	list_of_intgers = list(map(int,input().split()))

	print("Given list of integers:",list_of_intgers)

	print("Perfect numbers present in the list is: ")
	# Iteration through the each element of 
	# the list one by one
	for num in list_of_intgers :
		# function call
		checkPerfectNum(num)

Output

Enter list of integers:
14 20 6 78 28
Given list of integers: [14, 20, 6, 78, 28]
Perfect numbers present in the list is:
6 28

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