add async-fac1.py

async-fac1.py

@@ -0,0 +1,32 @@
+# https://djangostars.com/blog/asynchronous-programming-in-python-asyncio/
+
+import asyncio
+import time
+from datetime import datetime
+
+
+async def custom_sleep():
+    print('SLEEP {}n'.format(datetime.now()))
+    await asyncio.sleep(1)
+
+async def factorial(name, number):
+    f = 1
+    for i in range(2, number+1):
+        print('Task {}: Compute factorial({})'.format(name, i))
+        await custom_sleep()
+        f *= i
+    print('Task {}: factorial({}) is {}n'.format(name, number, f))
+
+
+start = time.time()
+loop = asyncio.get_event_loop()
+
+tasks = [
+    asyncio.ensure_future(factorial("A", 3)),
+    asyncio.ensure_future(factorial("B", 4)),
+]
+loop.run_until_complete(asyncio.wait(tasks))
+loop.close()
+
+end = time.time()
+print("Total time: {}".format(end - start))