While loop keeps going back to end condition-CodePudding

I'm just going over some python basics, and wrote some code that I thought would print every even element inside of a list:

def print_evens(numbers):
    """Prints all even numbers in the list
    """
    length = len(numbers)
    i = 0
    while i < length:
        if numbers[i] % 2 == 0:
            print (numbers[i])
            i  = 1
            
print_evens([1, 2, 3, 4, 5, 6])

I'm not sure why but the loop doesn't go past the end condition and just keeps cycling back and forth. I feel I'm missing something very simple.

If I had to guess where the problem lies, I'd say it's with the if statement, though I'm not sure what would be wrong about it.

CodePudding user response：

The problem is that when you start with 1 the variable i never get updated, because it's not even. So the solution is to increment the i every time without a condition:

while i < length:
        if numbers[i] % 2 == 0:
            print (numbers[i])
        i  = 1

CodePudding user response：

If you don't want to bother with indexes you can loop directly on the list items.

def print_evens(numbers):
    """Prints all even numbers in the list
    """
    for n in numbers:
        if n % 2 == 0:
            print(n)