2025-09-10:仓库迁移

4.迭代器与生成器/4.迭代协议.py

@@ -0,0 +1,31 @@
+# 这是标准的
+class Node:
+    def __init__(self, value):
+        self.value = value
+        self._children = []
+
+    def __repr__(self):
+        return "Node({})".format(self.value)
+
+    def add_child(self, node):
+        self._children.append(node)
+
+    def __iter__(self):
+        return iter(self._children)
+
+    def depth_first(self):
+        yield self
+        for child in self:
+            yield from child.depth_first()
+
+if __name__ == '__main__':
+    root = Node(0)
+    child1 = Node(1)
+    child2 = Node(2)
+    root.add_child(child1)
+    root.add_child(child2)
+    child1.add_child(Node(3))
+    child2.add_child(Node(4))
+
+    for ch in root.depth_first():
+        print(ch)