update from Atlas

attic/control/guido/guido1b.py

@@ -0,0 +1,30 @@
+"""
+Exemplo adaptado da mensagem do Guido van Rossum em:
+https://groups.google.com/forum/#!msg/python-tulip/bmphRrryuFk/aB45sEJUomYJ
+http://bit.ly/yieldfrom
+
+    >>> principal(ger2())
+    OK
+    None
+
+Visualização no PythonTutor: http://goo.gl/61CUcA
+
+"""
+
+def ger1():
+    val = yield 'OK'
+    print(val)
+    yield  # para evitar o StopIteration
+
+def ger2():
+    for i in ger1():
+        yield i
+
+def principal(g):
+    print(next(g))
+    g.send(42)
+
+
+# auto-teste
+import doctest
+doctest.testmod()