write a astar algrom

def astar(start, goal):
  # Create start and end node
  start_node = Node(None, start)
  start_node.g = start_node.h = start_node.f = 0
  end_node = Node(None, goal)
  end_node.g = end_node.h = end_node.f = 0

  # Initialize both open and closed list
  open_list = []
  closed_list = []

  # Add the start node
  open_list.append(start_node)

  # Loop until you find the end
  while len(open_list) > 0:

    # Get the current node
    current_node = open_list[0]
    current_index = 0
    for index, item in enumerate(open_list):
      if item.f < current_node.f:
        current_node = item
        current_index = index

    # Pop current off open list, add to closed list
    open_list.pop(current_index)
    closed_list.append(current_node