"""
 linked_list.py

 An example of a linked list in python : 
    <node> -> <node> -> <node> -> None

 To avoid confusion, here I'll refer to Python's built-in list as an "array".

 Jim Mahoney | cs.bennington.college | MIT License | March 2021
"""

class Node:
    """ A node in a linked list. """
    def __init__(self, name):
        self.name = name
        self.next = None
    def __str__(self):
        return "Node({})".format(self.name)

def nodes_to_str(node):
    """ Given the first node, return the whole linked list as a string. """
    # (Here I'm doing this with an explicit loop,
    #  but this could also be done will with recursion.)
    result = '['
    while node:
        result += str(node.name) + ', '
        node = node.next
    return result + ']'

def array_to_nodes(array):
    """ Given a python array, return the first node of a linked list. """
    previous = None
    for element in array:
        this = Node(element)
        if previous:
            previous.next = this
        else:
            root = this
        previous = this
    return root

def main():
    numbers = [1, 2, 3, 4]
    linkedlist = array_to_nodes(numbers)
    print(nodes_to_str(linkedlist))

main()