Various ruff fixes (#12821)

data_structures/stacks/stack.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from typing import Generic, TypeVar
+from typing import TypeVar
 
 T = TypeVar("T")
 
@@ -13,7 +13,7 @@ class StackUnderflowError(BaseException):
     pass
 
 
-class Stack(Generic[T]):
+class Stack[T]:
     """A stack is an abstract data type that serves as a collection of
     elements with two principal operations: push() and pop(). push() adds an
     element to the top of the stack, and pop() removes an element from the top

data_structures/stacks/stack_with_doubly_linked_list.py

@@ -3,19 +3,19 @@
 
 from __future__ import annotations
 
-from typing import Generic, TypeVar
+from typing import TypeVar
 
 T = TypeVar("T")
 
 
-class Node(Generic[T]):
+class Node[T]:
     def __init__(self, data: T):
         self.data = data  # Assign data
         self.next: Node[T] | None = None  # Initialize next as null
         self.prev: Node[T] | None = None  # Initialize prev as null
 
 
-class Stack(Generic[T]):
+class Stack[T]:
     """
     >>> stack = Stack()
     >>> stack.is_empty()

data_structures/stacks/stack_with_singly_linked_list.py

@@ -3,12 +3,12 @@
 from __future__ import annotations
 
 from collections.abc import Iterator
-from typing import Generic, TypeVar
+from typing import TypeVar
 
 T = TypeVar("T")
 
 
-class Node(Generic[T]):
+class Node[T]:
     def __init__(self, data: T):
         self.data = data
         self.next: Node[T] | None = None
@@ -17,7 +17,7 @@ class Node(Generic[T]):
         return f"{self.data}"
 
 
-class LinkedStack(Generic[T]):
+class LinkedStack[T]:
     """
     Linked List Stack implementing push (to top),
     pop (from top) and is_empty