python:singleton

차이

문서의 선택한 두 판 사이의 차이를 보여줍니다.

차이 보기로 링크

--- python:singleton [2016/02/01 06:38] – 만듦 rex8312
+++ python:singleton [2024/03/23 02:42] (현재) – 바깥 편집 127.0.0.1
@@ 줄 1: / 줄 1: @@
 ====== Python: Singleton ======
-  * http://stackoverflow.com/questions/6760685/creating-a-singleton-in-python
 <code python>
+# class Singleton(type):
+#     _instances = {}
+#     def __call__(cls, *args, **kwargs):
+#         if cls not in cls._instances:
+#             cls._instances[cls] = super(Singleton, cls).__call__(*args, **kwargs)
+#         return cls._instances[cls]
 class Singleton(type):
-    _instances = {}
+     _instances = {}
-    def __call__(cls, *args, **kwargs):
+     def __call__(cls, *args, **kwargs):
-        if cls not in cls._instances:
+         cls._instances.setdefault(cls, super().__call__(*args, **kwargs))
-            cls._instances[cls] = super(Singleton, cls).__call__(*args, **kwargs)
+         return cls._instances[cls]
-        return cls._instances[cls]
-#Python2
+# Python2
 class MyClass(BaseClass):
     __metaclass__ = Singleton
+    pass
-#Python3
+# Python3
 class MyClass(BaseClass, metaclass=Singleton):
     pass
+# Test
+for x in range(5):
+    MyClass().x = x
+    print(MyClass().x)
 </code>
+  * https://medium.com/techtofreedom/3-levels-of-understanding-the-singleton-pattern-in-python-4bf429a10438
+  * http://stackoverflow.com/questions/6760685/creating-a-singleton-in-python

python/singleton.1454308695.txt.gz · 마지막으로 수정됨: 2024/03/23 02:38 (바깥 편집)