Merge pull request #502 from anikamukherji/optimize-is-new-byte

remove import for isnewbytes

Author: jmadler

.travis.yml

@@ -2,14 +2,18 @@ sudo: false
 language: python
 cache: pip
 
+
 matrix:
   include:
     - python: 2.6
       env: TOXENV=py26
+      dist: trusty
     - python: 2.7
       env: TOXENV=py27
     - python: 3.3
       env: TOXENV=py33
+      dist: trusty
+      sudo: false
     - python: 3.4
       env: TOXENV=py34
     - python: 3.5

src/future/tests/base.py

@@ -342,6 +342,10 @@ def _futurize_test_script(self, filename='mytestscript.py', stages=(1, 2),
                         '----\n%s\n----' % f.read(),
                     )
             ErrorClass = (FuturizeError if 'futurize' in script else PasteurizeError)
+
+            if not hasattr(e, 'output'):
+                # The attribute CalledProcessError.output doesn't exist on Py2.6
+                e.output = None
             raise ErrorClass(msg, e.returncode, e.cmd, output=e.output)
         return output
 

src/future/utils/__init__.py

@@ -577,15 +577,14 @@ def isbytes(obj):
 
 def isnewbytes(obj):
     """
-    Equivalent to the result of ``isinstance(obj, newbytes)`` were
-    ``__instancecheck__`` not overridden on the newbytes subclass. In
-    other words, it is REALLY a newbytes instance, not a Py2 native str
+    Equivalent to the result of ``type(obj)  == type(newbytes)``
+    in other words, it is REALLY a newbytes instance, not a Py2 native str
     object?
+
+    Note that this does not cover subclasses of newbytes, and it is not
+    equivalent to ininstance(obj, newbytes)
     """
-    # TODO: generalize this so that it works with subclasses of newbytes
-    # Import is here to avoid circular imports:
-    from future.types.newbytes import newbytes
-    return type(obj) == newbytes
+    return type(obj).__name__ == 'newbytes'
 
 
 def isint(obj):

tests/test_future/test_utils.py

@@ -379,11 +379,14 @@ def test_chained_exceptions_stacktrace(self):
 class CustomException(Exception):
     if PY2:
         def __str__(self):
-            out = Exception.__str__(self)
-            if hasattr(self, '__cause__') and self.__cause__ and hasattr(self.__cause__, '__traceback__') and self.__cause__.__traceback__:
-                out += '\n\nThe above exception was the direct cause of the following exception:\n\n'
-                out += ''.join(traceback.format_tb(self.__cause__.__traceback__) + ['{}: {}'.format(self.__cause__.__class__.__name__, self.__cause__)])
-            return out
+            try:
+                out = Exception.__str__(self)
+                if hasattr(self, '__cause__') and self.__cause__ and hasattr(self.__cause__, '__traceback__') and self.__cause__.__traceback__:
+                    out += '\n\nThe above exception was the direct cause of the following exception:\n\n'
+                    out += ''.join(traceback.format_tb(self.__cause__.__traceback__) + ['{0}: {1}'.format(self.__cause__.__class__.__name__, self.__cause__)])
+                return out
+            except Exception as e:
+                print(e)
     else:
         pass