faif · faif · Dec 7, 2021 · Dec 6, 2021 · Dec 6, 2021 · Dec 6, 2021
diff --git a/patterns/behavioral/chaining_method.py b/patterns/behavioral/chaining_method.py
@@ -1,22 +1,25 @@
+from __future__ import annotations
+
+
 class Person:
-    def __init__(self, name, action):
+    def __init__(self, name: str, action: Action) -> None:
         self.name = name
         self.action = action
 
-    def do_action(self):
+    def do_action(self) -> Action:
         print(self.name, self.action.name, end=" ")
         return self.action
 
 
 class Action:
-    def __init__(self, name):
+    def __init__(self, name: str) -> None:
         self.name = name
 
-    def amount(self, val):
+    def amount(self, val: str) -> Action:
         print(val, end=" ")
         return self
 
-    def stop(self):
+    def stop(self) -> None:
         print("then stop")
 
 

diff --git a/patterns/behavioral/iterator_alt.py b/patterns/behavioral/iterator_alt.py
@@ -4,6 +4,7 @@
 *TL;DR
 Traverses a container and accesses the container's elements.
 """
+from __future__ import annotations
 
 
 class NumberWords:
@@ -17,14 +18,14 @@ class NumberWords:
         "five",
     )
 
-    def __init__(self, start, stop):
+    def __init__(self, start: int, stop: int) -> None:
         self.start = start
         self.stop = stop
 
-    def __iter__(self):  # this makes the class an Iterable
+    def __iter__(self) -> NumberWords:  # this makes the class an Iterable
         return self
 
-    def __next__(self):  # this makes the class an Iterator
+    def __next__(self) -> str:  # this makes the class an Iterator
         if self.start > self.stop or self.start > len(self._WORD_MAP):
             raise StopIteration
         current = self.start

diff --git a/patterns/behavioral/observer.py b/patterns/behavioral/observer.py
@@ -12,7 +12,7 @@
 from __future__ import annotations
 
 from contextlib import suppress
-from typing import List, Optional, Protocol
+from typing import Protocol
 
 
 # define a generic observer type
@@ -23,7 +23,7 @@ def update(self, subject: Subject) -> None:
 
 class Subject:
     def __init__(self) -> None:
-        self._observers: List[Observer] = []
+        self._observers: list[Observer] = []
 
     def attach(self, observer: Observer) -> None:
         if observer not in self._observers:
@@ -33,7 +33,7 @@ def detach(self, observer: Observer) -> None:
         with suppress(ValueError):
             self._observers.remove(observer)
 
-    def notify(self, modifier: Optional[Observer] = None) -> None:
+    def notify(self, modifier: Observer | None = None) -> None:
         for observer in self._observers:
             if modifier != observer:
                 observer.update(self)

diff --git a/patterns/behavioral/state.py b/patterns/behavioral/state.py
@@ -18,7 +18,7 @@ def scan(self):
         self.pos += 1
         if self.pos == len(self.stations):
             self.pos = 0
-        print("Scanning... Station is {} {}".format(self.stations[self.pos], self.name))
+        print(f"Scanning... Station is {self.stations[self.pos]} {self.name}")
 
 
 class AmState(State):

diff --git a/patterns/behavioral/strategy.py b/patterns/behavioral/strategy.py
@@ -10,7 +10,7 @@
 
 from __future__ import annotations
 
-from typing import Callable, Type
+from typing import Callable
 
 
 class DiscountStrategyValidator:  # Descriptor class for check perform
@@ -36,7 +36,7 @@ def __set__(self, obj: Order, value: Callable = None) -> None:
         else:
             setattr(obj, self.private_name, None)
 
-    def __get__(self, obj: object, objtype: Type = None):
+    def __get__(self, obj: object, objtype: type = None):
         return getattr(obj, self.private_name)
 
 

diff --git a/patterns/creational/prototype.py b/patterns/creational/prototype.py
@@ -20,16 +20,17 @@
 *TL;DR
 Creates new object instances by cloning prototype.
 """
+from __future__ import annotations
 
-from typing import Any, Dict
+from typing import Any
 
 
 class Prototype:
     def __init__(self, value: str = "default", **attrs: Any) -> None:
         self.value = value
         self.__dict__.update(attrs)
 
-    def clone(self, **attrs: Any) -> "Prototype":
+    def clone(self, **attrs: Any) -> Prototype:
         """Clone a prototype and update inner attributes dictionary"""
         # Python in Practice, Mark Summerfield
         # copy.deepcopy can be used instead of next line.
@@ -42,7 +43,7 @@ class PrototypeDispatcher:
     def __init__(self):
         self._objects = {}
 
-    def get_objects(self) -> Dict[str, Prototype]:
+    def get_objects(self) -> dict[str, Prototype]:
         """Get all objects"""
         return self._objects
 

diff --git a/patterns/fundamental/delegation_pattern.py b/patterns/fundamental/delegation_pattern.py
@@ -8,7 +8,7 @@
 
 from __future__ import annotations
 
-from typing import Any, Callable, Union
+from typing import Any, Callable
 
 
 class Delegator:
@@ -31,7 +31,7 @@ class Delegator:
     def __init__(self, delegate: Delegate):
         self.delegate = delegate
 
-    def __getattr__(self, name: str) -> Union[Any, Callable]:
+    def __getattr__(self, name: str) -> Any | Callable:
         attr = getattr(self.delegate, name)
 
         if not callable(attr):