Two new examples: print 'Hello World' every two seconds, using a callback and using a coroutine.

gvanrossum · gvanrossum · commit 276df9b47f52 · 2013-11-22T20:32:19.000-08:00
Thanks to Terry Reedy who suggested this exercise.
diff --git a/examples/hello_callback.py b/examples/hello_callback.py
@@ -0,0 +1,14 @@
+"""Print 'Hello World' every two seconds, using a callback."""
+
+import asyncio
+
+
+def print_and_repeat(loop):
+    print('Hello World')
+    loop.call_later(2, print_and_repeat, loop)
+
+
+if __name__ == '__main__':
+    loop = asyncio.get_event_loop()
+    print_and_repeat(loop)
+    loop.run_forever()
diff --git a/examples/hello_coroutine.py b/examples/hello_coroutine.py
@@ -0,0 +1,15 @@
+"""Print 'Hello World' every two seconds, using a coroutine."""
+
+import asyncio
+
+
+@asyncio.coroutine
+def greet_every_two_seconds():
+    while True:
+        print('Hello World')
+        yield from asyncio.sleep(2)
+
+
+if __name__ == '__main__':
+    loop = asyncio.get_event_loop()
+    loop.run_until_complete(greet_every_two_seconds())
