tests/extmod: Skip uselect test when CPython doesn't have poll().

stinos · dpgeorge · commit 06643a0df4e8 · 2018-10-30T14:49:23.000+11:00
CPython does not have an implementation of select.poll() on some
operating systems (Windows, OSX depending on version) so skip the
test in those cases instead of failing it.
diff --git a/tests/extmod/uselect_poll_basic.py b/tests/extmod/uselect_poll_basic.py
@@ -3,7 +3,8 @@
 except ImportError:
     try:
         import socket, select, errno
-    except ImportError:
+        select.poll  # Raises AttributeError for CPython implementations without poll()
+    except (ImportError, AttributeError):
         print("SKIP")
         raise SystemExit
 
