implement tornado style fake coroutine

tornado_style.py

@@ -0,0 +1,67 @@
+# -*- coding: utf-8 -*-
+
+
+from backports_abc import Generator as GeneratorType
+
+
+class Return(Exception):
+    def __init__(self, value=None):
+        self.value = value
+
+
+def coroutine(func):
+    def wrapper(*args, **kwargs):
+        def _dispatch(yielded):
+            if isinstance(yielded, GeneratorType):
+                return _execute_yield(yielded)
+            else:
+                return _send(yielded)
+
+        def _send(yielded):
+            try:
+                yielded = origin_gen.send(yielded)
+                return _dispatch(yielded)
+            except (StopIteration, Return) as e:
+                return getattr(e, 'value', None)
+            except Exception as error:
+                print 'terrible error happened: %r' % error
+
+        def _execute_yield(gen):
+            yielded = next(gen)
+            return _dispatch(yielded)
+
+        result = func(*args, **kwargs)
+        origin_gen = result
+        return _execute_yield(result)
+
+    return wrapper
+
+
+def get_value2():
+    return 10086
+
+
+def get_value1():
+    yield get_value2()
+
+
+@coroutine
+def test():
+    value1 = yield get_value1()
+    print 'got value1: %d' % value1
+
+    value2 = yield get_value2()
+    print 'got value2: %d' % value2
+
+    raise Return(value1 == value2)
+
+
+if __name__ == '__main__':
+    result = test()
+    print result
+
+"""
+>>> got value1: 10086
+>>> got value2: 10086
+>>> True
+"""