list_sum.py

valid = False

while not valid:
    list_size = int(input('How many numbers: '))
    if list_size <= 0:
        print ('Size must be positive')
    elif list_size % 2 != 0:
        print ('Size must be even')
    else:
        valid = True

numbers = list()
number_entered = 1
while number_entered <= list_size:
    number = int(input('Enter number {}: '.format(number_entered)))
    numbers.append(number)
    number_entered += 1

#  OR we could also use range to help us count the number of values 
#  entered

#for index in range(list_size):
#    number = int(input('Enter number {}: '.format(number_entered)))
#    numbers.append(number)

left_total = 0
for index in range(0, list_size // 2):
    left_total += numbers[index]

right_total = 0
for index in range(list_size // 2, list_size):
    right_total += numbers[index]

if left_total == right_total:
    print ("True")
else:
    print ("False")