input: Write a function to find the maximum number from a list of non-negative integers. The function should iterate through the list and update the maximum number found so far. If the list is empty, the function should return 0.
  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([10, 10, 10, 10])==10
  assert find_max([7])==7
  assert find_max([])==0
output: def find_max(list):
      max_num = 0
      for i in list:
          if i > max_num:
              max_num = i
      return max_num