input: Write a function to find the maximum number from a list of non-negative integers.
  def find_max(list): 
    max_num = 0
    for i in list: 
      if i > max_num: 
        max_num = i
    
    return max_num
  
  assert find_max([1, 3, 12, 5, 8, 10]) == 12
  assert find_max([0, 0, 0, 0]) == 0
  assert find_max([100, 200, 300, 50]) == 300
  assert find_max([4, 2, 9, 7]) == 9
  assert find_max([]) == 0
output: def find_max(list): 
    if not list:
      return 0
    max_num = list[0]
    for i in list: 
      if i > max_num: 
        max_num = i
    
    return max_num