ch11-24: clean up by @eumiro & sync with Atlas

19-coroutine/coroutil.py

@@ -0,0 +1,12 @@
+# tag::CORO_DECO[]
+from functools import wraps
+
+def coroutine(func):
+    """Decorator: primes `func` by advancing to first `yield`"""
+    @wraps(func)
+    def primer(*args,**kwargs):  # <1>
+        gen = func(*args,**kwargs)  # <2>
+        next(gen)  # <3>
+        return gen  # <4>
+    return primer
+# end::CORO_DECO[]