feat: 新增技能扩展N5一章相关示例源码

code/newsletter/N5/iter.py

@@ -0,0 +1,42 @@
+class CardGroup:
+    def __init__(self, container) -> None:
+        self.container = container
+        self.index = 0
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        if self.index < len(self.container):
+            value = self.container[self.index]
+            self.index += 1
+        else:
+            raise StopIteration
+        return value
+
+
+class Cards:
+    def __init__(self, values=None) -> None:
+        self._container = values or []
+
+    def __iter__(self):
+        return CardGroup(self._container)
+
+    def __getitem__(self, index):
+        return self._container[index]
+
+
+def main():
+    from collections.abc import Iterable
+
+    cards = Cards(list("JQK"))
+    print(f"Is the cards variable an iterale? {isinstance(cards, Iterable)}")
+
+    for card in cards:
+        print(card)
+
+    print(cards[1:])
+
+
+if __name__ == '__main__':
+    main()