Adds some more python 2 to 3 fixes

Problem:
This is just one of many python 2 to 3 fixes that need to be made.
This is a progressive enhancement

Analysis:
Various code portions in the resources class and tests were not
python 3 compatible. For instance, the BaseException class deprecated
its "message" attribute in 2.6 and removed it in 3.0. This needed to
be addressed in several areas. Additionally there were some changes
that needed to be made to loops over things that became iterators.

Tests:
f5/bigip/test/test_resource.py

Author: caphrim007

f5/bigip/resource.py

@@ -101,6 +101,9 @@
 from f5.sdk_exception import F5SDKError
 from f5.sdk_exception import UnsupportedMethod
 from requests.exceptions import HTTPError
+from six import iteritems
+from six import iterkeys
+from six import itervalues
 
 
 class MissingRequiredCommandParameter(F5SDKError):
@@ -195,7 +198,7 @@ def _missing_required_parameters(rqset, **kwargs):
 
     ::returns list
     """
-    key_set = set(kwargs.keys())
+    key_set = set(list(iterkeys(kwargs)))
     required_minus_received = rqset - key_set
     if required_minus_received != set():
         return list(required_minus_received)
@@ -307,7 +310,7 @@ def _check_exclusive_parameters(self, **kwargs):
         :raises ExclusiveAttributesPresent
         """
         if len(self._meta_data['exclusive_attributes']) > 0:
-            attr_set = set(kwargs.keys())
+            attr_set = set(list(iterkeys(kwargs)))
             ex_set = set(self._meta_data['exclusive_attributes'][0])
             common_set = attr_set.intersection(ex_set)
             if len(common_set) > 1:
@@ -479,9 +482,17 @@ def _update(self, **kwargs):
         # because these are subCollections and _meta_data and
         # other non-BIG-IP® attrs are not removed from the subCollections
         # See issue #146 for details
-        for key, value in self.__dict__.items():
+        tmp = dict()
+        for key, value in iteritems(self.__dict__):
+            # In Python2 versions we were changing a dictionary in place,
+            # but this cannot be done with an iterator as an error is raised.
+            # So instead we create a temporary holder for the modified dict
+            # and then re-assign it afterwards.
             if isinstance(value, Collection):
-                self.__dict__.pop(key, '')
+                pass
+            else:
+                tmp[key] = value
+        self.__dict__ = tmp
         data_dict = self.to_dict()
 
         # Remove any read-only attributes from our data_dict before we update
@@ -773,7 +784,7 @@ def _activate_URI(self, selfLinkuri):
 
         # attrs local alias
         attribute_reg = self._meta_data.get('attribute_registry', {})
-        attrs = attribute_reg.values()
+        attrs = list(itervalues(attribute_reg))
         attrs.append(Stats)
 
         (scheme, domain, path, qarg, frag) = urlparse.urlsplit(selfLinkuri)

f5/bigip/test/test_resource.py

@@ -81,22 +81,22 @@ def test_Resource__local_update_IncompatibleKeys():
     r = Resource(mock.MagicMock())
     with pytest.raises(DeviceProvidesIncompatibleKey) as DPIKIO:
         r._local_update({"_meta_data": "foo"})
-    assert DPIKIO.value.message ==\
+    assert str(DPIKIO.value) ==\
         "Response contains key '_meta_data' which is incompatible"\
         " with this API!!\n Response json: {'_meta_data': 'foo'}"
     with pytest.raises(DeviceProvidesIncompatibleKey) as DPIKIO:
         r._local_update({"__MANGLENAME": "foo"})
-    assert DPIKIO.value.message ==\
+    assert str(DPIKIO.value) ==\
         "Device provided '__MANGLENAME' which is disallowed,"\
         " it mangles into a Python non-public attribute."
     with pytest.raises(DeviceProvidesIncompatibleKey) as DPIKIO:
         r._local_update({"for": "foo"})
-    assert DPIKIO.value.message ==\
+    assert str(DPIKIO.value) ==\
         "Device provided 'for' which is disallowed because"\
         " it's a Python keyword."
     with pytest.raises(DeviceProvidesIncompatibleKey) as DPIKIO:
         r._local_update({"%abcd": "foo"})
-    assert DPIKIO.value.message ==\
+    assert str(DPIKIO.value) ==\
         "Device provided '%abcd' which is disallowed because"\
         " it's not a valid Python 2.7 identifier."
 
@@ -132,19 +132,26 @@ def test_missing_required_creation_parameter(self):
         r._meta_data['required_creation_parameters'] = set(['NONEMPTY'])
         with pytest.raises(MissingRequiredCreationParameter) as MRCPEIO:
             r.create(partition="Common", name='CreateTest')
-        assert MRCPEIO.value.message ==\
+        assert str(MRCPEIO.value) ==\
             "Missing required params: ['NONEMPTY']"
 
     def test_KindTypeMismatch(self):
+        expected_result = (
+            "For instances of type ''Virtual'' the "
+            "corresponding kind must be ''tm:ltm:virtual:virtualstate'' "
+            "but creation returned "
+            "JSON with kind: 'tm:'"
+        )
         r = Virtual(mock.MagicMock())
+
         r._meta_data['bigip']._meta_data['icr_session'].post.return_value =\
-            MockResponse({u"kind": u"tm:"})
-        with pytest.raises(KindTypeMismatch) as KTMmEIO:
+            MockResponse({"kind": "tm:"})
+
+        with pytest.raises(KindTypeMismatch) as error:
             r.create(partition="Common", name="test_create")
-        assert KTMmEIO.value.message ==\
-            "For instances of type ''Virtual'' the corresponding kind must "\
-            "be ''tm:ltm:virtual:virtualstate'' but creation returned "\
-            "JSON with kind: u'tm:'"
+
+        result = error.value.args[0]
+        assert result == expected_result
 
     def test_success(self, fake_vs):
         x = fake_vs.create(partition="Common", name="test_create")
@@ -217,7 +224,7 @@ def test__create_with_Collision():
     r._meta_data['uri'] = 'URI'
     with pytest.raises(URICreationCollision) as UCCEIO:
         r.create(uri='URI')
-    assert UCCEIO.value.message ==\
+    assert str(UCCEIO.value) ==\
         "There was an attempt to assign a new uri to this resource,"\
         " the _meta_data['uri'] is URI and it should not be changed."
 
@@ -235,7 +242,7 @@ def test__check_generation_with_mismatch(self):
         r.generation = 1
         with pytest.raises(GenerationMismatch) as GMEIO:
             r.update(a=u"b", force=False)
-        assert GMEIO.value.message ==\
+        assert str(GMEIO.value) ==\
             'The generation of the object on the BigIP (0)'\
             ' does not match the current object(1)'
 
@@ -267,7 +274,6 @@ def test_Collection_removal(self):
         r.update(a=u"b")
         submitted = r._meta_data['bigip']. \
             _meta_data['icr_session'].put.call_args[1]['json']
-
         assert 'contained' not in submitted
 
     def test_read_only_removal(self):
@@ -366,7 +372,7 @@ def test_read_only_validate(self):
         r.generation = 0
         with pytest.raises(AttemptedMutationOfReadOnly) as AMOROEIO:
             r.modify(READONLY=True)
-        assert "READONLY" in AMOROEIO.value.message
+        assert "READONLY" in str(AMOROEIO.value)
 
     def test_reduce_boolean_removes_enabled(self, fake_rsrc):
         fake_rsrc.modify(enabled=False)
@@ -425,7 +431,7 @@ def test_invalid_force(self):
         r._meta_data['bigip']._meta_data = {'icr_session': mock_session}
         with pytest.raises(InvalidForceType) as IFTEIO:
             r.delete(force='true')
-        assert IFTEIO.value.message == 'force parameter must be type bool'
+        assert str(IFTEIO.value) == 'force parameter must be type bool'
 
 
 class Element(Resource):
@@ -469,7 +475,7 @@ def test_unregistered_kind(self):
         c.generation = 0
         with pytest.raises(UnregisteredKind) as UKEIO:
             c.get_collection()
-        assert UKEIO.value.message ==\
+        assert str(UKEIO.value) ==\
             "'tm:' is not registered!"
 
 
@@ -479,15 +485,15 @@ def test_missing_required_params(self):
         r._meta_data['required_load_parameters'] = set(['IMPOSSIBLE'])
         with pytest.raises(MissingRequiredReadParameter) as MRREIO:
             r.load(partition='Common', name='test_load')
-        assert MRREIO.value.message ==\
+        assert str(MRREIO.value) ==\
             "Missing required params: ['IMPOSSIBLE']"
 
     def test_requests_params_collision(self):
         r = Resource(mock.MagicMock())
         with pytest.raises(RequestParamKwargCollision) as RPKCEIO:
             r.load(partition='Common', name='test_load',
                    requests_params={'partition': 'ERROR'})
-        assert RPKCEIO.value.message ==\
+        assert str(RPKCEIO.value) ==\
             "Requests Parameter 'partition' collides with a load parameter"\
             " of the same name."