address OSError hierarchy Fixes benjaminp#311

six.py

@@ -28,6 +28,11 @@
 import sys
 import types
 
+try:
+    from select import error as select_error
+except ImportError:
+    select_error = None
+
 __author__ = "Benjamin Peterson <[email protected]>"
 __version__ = "1.13.0"
 
@@ -43,6 +48,7 @@
     class_types = type,
     text_type = str
     binary_type = bytes
+    os_errors = OSError,
 
     MAXSIZE = sys.maxsize
 else:
@@ -71,6 +77,12 @@ def __len__(self):
             MAXSIZE = int((1 << 63) - 1)
         del X
 
+    os_errors = (
+        (EnvironmentError, select_error)
+        if select_error
+        else EnvironmentError,
+    )
+
 
 def _add_doc(func, doc):
     """Add documentation to a function."""