Sum Of even numbers among the input of N numbers

Question

How to find the sum of even numbers from entered N numbers? i tried the below code but cant find the required output.

n=int(input('Enter the number:'))
if(n<=0):
    print('Enter a valid number')
else:
    sum=0
    count = 0
    while(n>0):
        for count in range (i % 2 ==0)
            sum+=n
             n-=1            
    print(sum)

Answer 1

this was more or less solved in comments by passing a range with step to sum . Most pythonic way:

sum(range(2,n+1,2))

In that particular case, this can be improved to use a simple math expression to reduce complexity

since the sum of integers from 1 to n is n*(n+1)//2 , the sum of even numbers is the double, with n divided by 2 ( n is even here but it also works with odd numbers thanks to integer division) so:

n//2 * (n//2+1)