Simple metaclass snippet demoing call and new.

cthulahoops · cthulahoops · commit dce628dfad76 · 2018-11-02T17:16:46.000Z
diff --git a/tests/snippets/metaclasses.py b/tests/snippets/metaclasses.py
@@ -0,0 +1,25 @@
+class MC(type):
+    classes = []
+    count = 0
+
+    def __new__(cls, name, bases, namespace):
+        MC.classes.append(name)
+        return type.__new__(cls, name, bases, namespace)
+
+    def __call__(cls):
+        MC.count += 1
+        return type.__call__(cls, MC.count)
+
+class C(object, metaclass=MC):
+    def __new__(cls, count):
+        self = object.__new__(cls)
+        self.count = count
+        return self
+
+class D(object, metaclass=MC):
+    pass
+
+assert MC == type(C)
+assert C == type(C())
+assert MC.classes == ['C', 'D']
+assert C().count == 2
