python_ds

LinkedList.py

class LinkedListNode(object):
    def __init__(self, data=None, next_node=None):
        self.next_node = next_node
        self.data = data


class LinkedList(object):
    def __init__(self):
        self.head = None

    def append(self, data):
        new_node = LinkedListNode(data, None)
        if self.head is None:
            self.head = new_node
        else:
            temp = self.head
            while temp.next_node:
                temp = temp.next_node
            temp.next_node = new_node

    def __repr__(self):
        # Function for printing the LL in human readable format
        temp = self.head
        repr_str = ""
        while temp:
            repr_str += str(temp.data) + " "
            temp = temp.next_node
        return repr_str

    def delete(self, pos):
        if pos == 0 and self.head:
            del_node = self.head
            self.head = self.head.next
            return del_node
        temp = self.head
        try:
            for _ in range(pos - 1):
                temp = temp.next_node
        except AttributeError:  # testing if pos > len
            raise IndexError("Position greater than length of list")
            return
        del_node = temp.next_node
        temp.next_node = del_node.next_node
        return del_node

Just a typo in delete method: if pos==0 after assigning self.head to del_node, the next node becomes the head so: it's not "self.head=self.head.next" but self.head=self.head.next_node