input: Write a function to identify the number of even numbers present in a given list of numbers. If the given list is empty, return 0.
  def countEvenNum(list):
      return len([x for x in list if x % 2 == 0])
  
  assert countEvenNum([1, 2, 3, 4, 5])==2
  assert countEvenNum([2, 4, 6, 8])==4
  assert countEvenNum([1, 3, 5, 7])==0
  assert countEvenNum([])==0
output: def countEvenNum(list):
      return len([x for x in list if x % 2 == 0])