LinkedList.py

class Node:
    """Represents a Node in a Linked List"""

    def __init__(self, item):
        self.data = item
        self.next = None

    def __str__(self):
        return str(self.data)


class LinkedList:
    """Represents a Single Linked List"""

    def __init__(self):
        self.head = None

    def add(self, new_item):
        """Creates a new Node with 'new_item' and adds to the front"""
        node = Node(new_item)
        node.next = self.head
        self.head = node

        return self.head

    def __str__(self):
        """Returns a String that represents all the nodes from head in a list"""
        output = []
        curr = self.head
        while curr:
            output.append(curr.data)
            curr = curr.next
        return str(output)

    def delete(self, item):
        """Deletes the target item from the lined list, if exists"""
        # case 2: delete help
        if self.head.data == item:
            self.head = self.head.next
            return self.head

        # case 1: delete a middle Node
        prev = None
        curr = self.head
        while curr and curr.data != item:
            prev = curr
            curr = curr.next
        if curr:  # if curr != None
            prev.next = curr.next

        return self.head


llist = LinkedList()
llist.add(5)
llist.add(10)
llist.add(15)
llist.delete(20)
print(llist)