input: Write a function to find the maximum number from a list of non-negative integers. Return the maximum number found.
  
  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([4, 8, 2, 6])==8
  assert find_max([0, 0, 0, 0])==0
  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