input: Write a function to iterate over a list of numbers and print only the even numbers. The function should accept a list of integers as its parameter. If the list is empty, the function should print an empty line.
  assert even_numbers([1, 2, 3, 4, 5, 6, 7, 8, 9, 10])==[2, 4, 6, 8, 10]
  assert even_numbers([11, 13, 15, 17])==[]
  assert even_numbers([0, 2, 4, 6, 8, 10])==[0, 2, 4, 6, 8, 10]
  assert even_numbers([])==[]
  assert even_numbers([-2, -1, 0, 1, 2])==[-2, 0, 2]
output: def even_numbers(numbers):
      return [num for num in numbers if num % 2 == 0]