Catch SyntaxError when importing asyncio for convenience: ignore SyntaxError

caused by "yield from" if tulip is in the Python path

3 files changed, 9 insertions, 15 deletions

diff --git a/trollius/coroutines.py b/trollius/coroutines.py
index 5c11be2..1c842fb 100644
--- a/trollius/coroutines.py
+++ b/trollius/coroutines.py
@@ -8,10 +8,6 @@ import os
 import sys
 import traceback
 import types
-try:
-    import asyncio
-except ImportError:
-    asyncio = None
 
 from . import compat
 from . import events
@@ -281,13 +277,13 @@ def iscoroutinefunction(func):
 
 
 _COROUTINE_TYPES = (types.GeneratorType, CoroWrapper)
-if asyncio is not None:
+if events.asyncio is not None:
     # Accept also asyncio CoroWrapper for interoperability
-    if hasattr(asyncio, 'coroutines'):
-        _COROUTINE_TYPES += (asyncio.coroutines.CoroWrapper,)
+    if hasattr(events.asyncio, 'coroutines'):
+        _COROUTINE_TYPES += (events.asyncio.coroutines.CoroWrapper,)
     else:
         # old Tulip/Python versions
-        _COROUTINE_TYPES += (asyncio.tasks.CoroWrapper,)
+        _COROUTINE_TYPES += (events.asyncio.tasks.CoroWrapper,)
 
 def iscoroutine(obj):
     """Return True if obj is a coroutine object."""
diff --git a/trollius/events.py b/trollius/events.py
index 7fa658d..131399b 100644
--- a/trollius/events.py
+++ b/trollius/events.py
@@ -19,7 +19,9 @@ import sys
 from trollius import compat
 try:
     import asyncio
-except ImportError:
+except (ImportError, SyntaxError):
+    # ignore SyntaxError for convenience: ignore SyntaxError caused by "yield
+    # from" if asyncio module is in the Python path
     asyncio = None
 
 
diff --git a/trollius/futures.py b/trollius/futures.py
index 45bb18d..fa0a7e7 100644
--- a/trollius/futures.py
+++ b/trollius/futures.py
@@ -8,10 +8,6 @@ __all__ = ['CancelledError', 'TimeoutError',
 import logging
 import sys
 import traceback
-try:
-    import asyncio
-except ImportError:
-    asyncio = None
 
 from . import events
 from . import executor
@@ -393,9 +389,9 @@ class Future(object):
                 result = other.result()
                 self.set_result(result)
 
-if asyncio is not None:
+if events.asyncio is not None:
     # Accept also asyncio Future objects for interoperability
-    _FUTURE_CLASSES = (Future, asyncio.Future)
+    _FUTURE_CLASSES = (Future, events.asyncio.Future)
 else:
     _FUTURE_CLASSES = Future