Updated and solved the issue in circular_linked_list_list.py

[PranavYewale]

Added a length attribute to the CircularLinkedList class to track the length of the linked list.

Updated the len method to return the length attribute instead of calculating the length using a loop. This change improves the space complexity of the len method to O(1).

Updated the insert_tail and insert_head methods to update the length attribute directly instead of calling the len function. This change ensures that the length is accurately maintained.

Updated the insert_nth method to include a check for the index range and raise an IndexError if the index is out of range. This provides better error handling.

Added a delete_tail method that deletes the last node of the linked list. This method calls the delete_nth method with the index set to self.length - 1 and the update_length flag set to True. This ensures that the length is correctly updated when the last node is deleted.

Updated the delete_nth method to include an update_length parameter. When this parameter is set to True, the method will update the length attribute after deleting the node.

[amirsoroush]

I'm agree with you that keeping track of the length would give us O(1) time complexity in those operations. Currently in insert_tail method we calculate the length twice: Once in insert_tail and once when it get delegated to insert_nth.

But this idea got rejected in the past. You may want to look at the comments here and here.

[rohan472000]

Look in ruff issue, to fix that use ruff . --fix before pushing.

[tianyizheng02]

Ignoring the arguments for and against having a length attribute, this PR breaks things in other significant ways: removing all imports, removing a required class, removing the test function, and removing the __main__ block.