draft of coroutine examples

control/flatten.py

@@ -0,0 +1,21 @@
+"""
+
+    >>> items = [1, 2, [3, 4, [5, 6], 7], 8]
+    >>> flatten(items)
+    <generator object flatten at 0x73bd9c>
+    >>> list(flatten(items))
+    [1, 2, 3, 4, 5, 6, 7, 8]
+    >>> mixed_bag = [1, 'spam', 2, [3, 'eggs', 4], {'x': 1, 'y': 2}]
+    >>> list(flatten(mixed_bag))
+    [1, 'spam', 2, 3, 'eggs', 4, 'y', 'x']
+"""
+
+
+from collections import Iterable
+
+def flatten(items):
+    for x in items:
+        if isinstance(x, Iterable) and not isinstance(x, (str, bytes)):
+            yield from flatten(x)
+        else:
+            yield x