lst = [1, 2, 3, 4]

## Iteration through a list with a while loop ##
# Print elements
i = 0
while i < len(lst):
    print(lst[i])
    i += 1

def sum_of_evens(lst):
    """ Return the sum of the even numbers in lst. """
    i, total = 0, 0
    while i < len(lst):
        if lst[i] % 2 == 0:
            total += lst[i]
        i += 1
    return total


## Iteration through a list with a for loop ##
# Print elements
for e in lst:
    print(e)

def sum_of_evens_for(lst):
    """ Return the sum of the even numbers in lst. """
    total = 0
    for e in lst:
        if e % 2 == 0:
            total += e
    return total


## Iteration through a range ##
def print_odds(n):
    """ Print all the odd numbers from 1 to n. """
    for x in range(n):
        if x % 2 == 1:
            print(x)

def print_n_times(x, n):
    """ Print the value of x n times. """
    for _ in range(n):
        print(x)