Minor changes

Mostly minor changes to make code more compliant with
proper coding style, also some repetitions are removed.
diff --git a/reclass/__init__.py b/reclass/__init__.py
index 2167a30..d5f3410 100644
--- a/reclass/__init__.py
+++ b/reclass/__init__.py
@@ -19,7 +19,7 @@
     storage_class = StorageBackendLoader(storage_type).load()
     return MemcacheProxy(storage_class(nodes_uri, classes_uri, compose_node_name, **kwargs))
 
-def get_path_mangler(storage_type,**kwargs):
+def get_path_mangler(storage_type, **kwargs):
     return StorageBackendLoader(storage_type).path_mangler()
 
 def output(data, fmt, pretty_print=False, no_refs=False):
diff --git a/reclass/core.py b/reclass/core.py
index d07b232..e3142af 100644
--- a/reclass/core.py
+++ b/reclass/core.py
@@ -23,7 +23,6 @@
 from six import iteritems
 
 from reclass.settings import Settings
-from reclass.output.yaml_outputter import ExplicitDumper
 from reclass.datatypes import Entity, Classes, Parameters, Exports
 from reclass.errors import MappingFormatError, ClassNameResolveError, ClassNotFound, InvQueryClassNameResolveError, InvQueryClassNotFound, InvQueryError, InterpolationError, ResolveError
 from reclass.values.parser import Parser
@@ -153,8 +152,16 @@
 
     def _get_automatic_parameters(self, nodename, environment):
         if self._settings.automatic_parameters:
-            return Parameters({ '_reclass_': { 'name': { 'full': nodename, 'short': nodename.split('.')[0] },
-                                               'environment': environment } }, self._settings, '__auto__')
+            pars = {
+                '_reclass_': {
+                    'name': {
+                        'full': nodename,
+                        'short': nodename.split('.')[0]
+                    },
+                'environment': environment
+                }
+            }
+            return Parameters(pars, self._settings, '__auto__')
         else:
             return Parameters({}, self._settings, '')
 
@@ -163,13 +170,12 @@
         for nodename in self._storage.enumerate_nodes():
             try:
                 node_base = self._storage.get_node(nodename, self._settings)
-                if node_base.environment == None:
+                if node_base.environment is None:
                     node_base.environment = self._settings.default_environment
             except yaml.scanner.ScannerError as e:
                 if self._settings.inventory_ignore_failed_node:
                     continue
-                else:
-                    raise
+                raise
 
             if all_envs or node_base.environment == environment:
                 try:
@@ -221,7 +227,8 @@
             raise
 
     def _nodeinfo_as_dict(self, nodename, entity):
-        ret = {'__reclass__' : {'node': entity.name, 'name': nodename,
+        ret = {'__reclass__' : {'node': entity.name,
+                                'name': nodename,
                                 'uri': entity.uri,
                                 'environment': entity.environment,
                                 'timestamp': Core._get_timestamp()
diff --git a/reclass/datatypes/applications.py b/reclass/datatypes/applications.py
index 90ae54c..4f6ee10 100644
--- a/reclass/datatypes/applications.py
+++ b/reclass/datatypes/applications.py
@@ -28,18 +28,14 @@
 
     def __init__(self, iterable=None,
                  negation_prefix=DEFAULT_NEGATION_PREFIX):
-        self._negation_prefix = negation_prefix
+        self.negation_prefix = negation_prefix
         self._offset = len(negation_prefix)
         self._negations = []
         super(Applications, self).__init__(iterable)
 
-    @property
-    def negation_prefix(self):
-        return self._negation_prefix
-
     def append_if_new(self, item):
         self._assert_is_string(item)
-        if item.startswith(self._negation_prefix):
+        if item.startswith(self.negation_prefix):
             item = item[self._offset:]
             self._negations.append(item)
             try:
@@ -64,6 +60,6 @@
 
     def __repr__(self):
         contents = self._items + \
-                ['%s%s' % (self._negation_prefix, i) for i in self._negations]
+                ['%s%s' % (self.negation_prefix, i) for i in self._negations]
         return "%s(%r, %r)" % (self.__class__.__name__, contents,
-                               str(self._negation_prefix))
+                               str(self.negation_prefix))
diff --git a/reclass/datatypes/classes.py b/reclass/datatypes/classes.py
index 5270e28..fa9cbcf 100644
--- a/reclass/datatypes/classes.py
+++ b/reclass/datatypes/classes.py
@@ -57,7 +57,7 @@
 
     def _assert_is_string(self, item):
         if not isinstance(item, six.string_types):
-            raise TypeError('%s instances can only contain strings, '\
+            raise TypeError('%s instances can only contain strings, '
                             'not %s' % (self.__class__.__name__, type(item)))
 
     def _assert_valid_characters(self, item):
diff --git a/reclass/datatypes/entity.py b/reclass/datatypes/entity.py
index 8133de5..2e0e1e4 100644
--- a/reclass/datatypes/entity.py
+++ b/reclass/datatypes/entity.py
@@ -35,7 +35,6 @@
         self._environment = environment
 
     name = property(lambda s: s._name)
-    short_name = property(lambda s: s._short_name)
     uri = property(lambda s: s._uri)
     classes = property(lambda s: s._classes)
     applications = property(lambda s: s._applications)
@@ -61,10 +60,10 @@
         return received_value
 
     def merge(self, other):
-        self._classes.merge_unique(other._classes)
-        self._applications.merge_unique(other._applications)
-        self._parameters.merge(other._parameters)
-        self._exports.merge(other._exports)
+        self._classes.merge_unique(other.classes)
+        self._applications.merge_unique(other.applications)
+        self._parameters.merge(other.parameters)
+        self._exports.merge(other.exports)
         self._name = other.name
         self._uri = other.uri
         self._parameters._uri = other.uri
@@ -91,12 +90,12 @@
 
     def __eq__(self, other):
         return isinstance(other, type(self)) \
-                and self._applications == other._applications \
-                and self._classes == other._classes \
-                and self._parameters == other._parameters \
-                and self._exports == other._exports \
-                and self._name == other._name \
-                and self._uri == other._uri
+                and self._applications == other.applications \
+                and self._classes == other.classes \
+                and self._parameters == other.parameters \
+                and self._exports == other.exports \
+                and self._name == other.name \
+                and self._uri == other.uri
 
     def __ne__(self, other):
         return not self.__eq__(other)
diff --git a/reclass/datatypes/exports.py b/reclass/datatypes/exports.py
index 04ab200..984a15a 100644
--- a/reclass/datatypes/exports.py
+++ b/reclass/datatypes/exports.py
@@ -23,9 +23,6 @@
     def __init__(self, mapping, settings, uri):
         super(Exports, self).__init__(mapping, settings, uri)
 
-    def __repr__(self):
-        return '%s(%r)' % (self.__class__.__name__, self._base)
-
     def delete_key(self, key):
         self._base.pop(key, None)
         self._unrendered.pop(key, None)
diff --git a/reclass/storage/loader.py b/reclass/storage/loader.py
index aab554a..0a66a66 100644
--- a/reclass/storage/loader.py
+++ b/reclass/storage/loader.py
@@ -32,5 +32,6 @@
     def path_mangler(self, name='path_mangler'):
         function = getattr(self._module, name, None)
         if function is None:
-            raise AttributeError('Storage backend class {0} does not export "{1}"'.format(self._name, name))
+            raise AttributeError('Storage backend class {0} does not export '
+                                 '"{1}"'.format(self._name, name))
         return function
diff --git a/reclass/values/value.py b/reclass/values/value.py
index 736e01a..451617e 100644
--- a/reclass/values/value.py
+++ b/reclass/values/value.py
@@ -24,7 +24,7 @@
         self._settings = settings
         self.uri = uri
         self.overwrite = False
-        self._constant = False
+        self.constant = False
         if isinstance(value, string_types):
             if parse_string:
                 try:
@@ -41,14 +41,6 @@
         else:
             self._item = ScaItem(value, self._settings)
 
-    @property
-    def constant(self):
-        return self._constant
-
-    @constant.setter
-    def constant(self, constant):
-        self._constant = constant
-
     def item_type(self):
         return self._item.type
 
@@ -74,8 +66,7 @@
     def needs_all_envs(self):
         if self._item.has_inv_query:
             return self._item.needs_all_envs
-        else:
-            return False
+        return False
 
     def ignore_failed_render(self):
         return self._item.ignore_failed_render