Problem

Given a list of integers, write a Python function to return the sum of the positive integers in the list. If the list is empty, return 0.
Input: [1, -2, 3, 4, -5]
Output: 11

Solution

def sum_positive(lst):
    return sum(x for x in lst if x > 0)

# This solution is optimal because it uses a generator expression to filter the list and then sum the positive integers.
# This is optimal because it is a one-liner and it is also very readable.