data_structures.linked_list.doubly_linked_list_two

• A linked list is similar to an array, it holds values. However, links in a linked

  list do not have indexes.

• This is an example of a double ended, doubly linked list.

• Each link references the next link and the previous one.

• A Doubly Linked List (DLL) contains an extra pointer, typically called previous

  pointer, together with next pointer and data which are there in singly linked list.

• Advantages over SLL - It can be traversed in both forward and backward direction.

  Delete operation is more efficient

Classes

LinkedList
LinkedListIterator
Node

Functions

create_linked_list(→ None)

Module Contents

class data_structures.linked_list.doubly_linked_list_two.LinkedList

__contains__(value: int)

__iter__()

__str__()

delete_value(value)

get_head_data()

get_node(item: int) → Node

get_tail_data()

insert(value: int) → None

insert_after_node(node: Node, node_to_insert: Node) → None

insert_at_position(position: int, value: int) → None

insert_before_node(node: Node, node_to_insert: Node) → None

is_empty()

static remove_node_pointers(node: Node) → None

set_head(node: Node) → None

set_tail(node: Node) → None

head = None

tail = None

class data_structures.linked_list.doubly_linked_list_two.LinkedListIterator(head)

__iter__()

__next__()

current

class data_structures.linked_list.doubly_linked_list_two.Node(data: int, previous=None, next_node=None)

__str__() → str

get_data() → int

get_next()

get_previous()

data

next

previous

data_structures.linked_list.doubly_linked_list_two.create_linked_list() → None

>>> new_linked_list = LinkedList()
>>> new_linked_list.get_head_data() is None
True
>>> new_linked_list.get_tail_data() is None
True
>>> new_linked_list.is_empty()
True
>>> new_linked_list.insert(10)
>>> new_linked_list.get_head_data()
10
>>> new_linked_list.get_tail_data()
10
>>> new_linked_list.insert_at_position(position=3, value=20)
>>> new_linked_list.get_head_data()
10
>>> new_linked_list.get_tail_data()
20
>>> new_linked_list.set_head(Node(1000))
>>> new_linked_list.get_head_data()
1000
>>> new_linked_list.get_tail_data()
20
>>> new_linked_list.set_tail(Node(2000))
>>> new_linked_list.get_head_data()
1000
>>> new_linked_list.get_tail_data()
2000
>>> for value in new_linked_list:
...    print(value)
1000
10
20
2000
>>> new_linked_list.is_empty()
False
>>> for value in new_linked_list:
...    print(value)
1000
10
20
2000
>>> 10 in new_linked_list
True
>>> new_linked_list.delete_value(value=10)
>>> 10 in new_linked_list
False
>>> new_linked_list.delete_value(value=2000)
>>> new_linked_list.get_tail_data()
20
>>> new_linked_list.delete_value(value=1000)
>>> new_linked_list.get_tail_data()
20
>>> new_linked_list.get_head_data()
20
>>> for value in new_linked_list:
...    print(value)
20
>>> new_linked_list.delete_value(value=20)
>>> for value in new_linked_list:
...    print(value)
>>> for value in range(1,10):
...    new_linked_list.insert(value=value)
>>> for value in new_linked_list:
...    print(value)
1
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