Fix lint errors

4 files changed, 13 insertions, 11 deletions

diff --git a/astroid/decorators.py b/astroid/decorators.py
index a0625f2c..a8a92ef3 100644
--- a/astroid/decorators.py
+++ b/astroid/decorators.py
@@ -80,7 +80,7 @@ def path_wrapper(func):
         if context is None:
             context = contextmod.InferenceContext()
         if context.push(node):
-            return
+            return None
 
         yielded = set()
         generator = _func(node, context, **kwargs)
@@ -100,7 +100,7 @@ def path_wrapper(func):
             # comment in raise_if_nothing_inferred.
             if error.args:
                 return error.args[0]
-            return
+            return None
 
     return wrapped
 
diff --git a/astroid/inference.py b/astroid/inference.py
index 5467736e..8c862ee9 100644
--- a/astroid/inference.py
+++ b/astroid/inference.py
@@ -327,18 +327,18 @@ def infer_subscript(self, context=None):
     try:
         value = next(self.value.infer(context))
     except StopIteration:
-        return
+        return None
     if value is util.Uninferable:
         yield util.Uninferable
-        return
+        return None
 
     try:
         index = next(self.slice.infer(context))
     except StopIteration:
-        return
+        return None
     if index is util.Uninferable:
         yield util.Uninferable
-        return
+        return None
 
     # Try to deduce the index value.
     index_value = _SUBSCRIPT_SENTINEL
@@ -367,7 +367,7 @@ def infer_subscript(self, context=None):
     # is the same as the original subscripted object.
     if self is assigned or assigned is util.Uninferable:
         yield util.Uninferable
-        return
+        return None
     for inferred in assigned.infer(context):
         yield inferred
 
@@ -398,7 +398,7 @@ def _infer_boolop(self, context=None):
         values = [value.infer(context=context) for value in values]
     except exceptions.InferenceError:
         yield util.Uninferable
-        return
+        return None
 
     for pair in itertools.product(*values):
         if any(item is util.Uninferable for item in pair):
diff --git a/astroid/protocols.py b/astroid/protocols.py
index 7ae93976..641605c5 100644
--- a/astroid/protocols.py
+++ b/astroid/protocols.py
@@ -354,7 +354,7 @@ nodes.Arguments.assigned_stmts = arguments_assigned_stmts
 def assign_assigned_stmts(self, node=None, context=None, asspath=None):
     if not asspath:
         yield self.value
-        return
+        return None
     for inferred in _resolve_asspart(self.value.infer(context), asspath, context):
         yield inferred
     # Explicit StopIteration to return error information, see comment
@@ -503,7 +503,7 @@ def with_assigned_stmts(self, node=None, context=None, asspath=None):
     try:
         mgr = next(mgr for (mgr, vars) in self.items if vars == node)
     except StopIteration:
-        return
+        return None
     if asspath is None:
         for result in _infer_context_manager(self, mgr, context):
             yield result
diff --git a/astroid/scoped_nodes.py b/astroid/scoped_nodes.py
index 0c8b6476..99a275c9 100644
--- a/astroid/scoped_nodes.py
+++ b/astroid/scoped_nodes.py
@@ -2511,7 +2511,7 @@ class ClassDef(mixins.FilterStmtsMixin, LocalsDictNodeNG,
     def _islots(self):
         """ Return an iterator with the inferred slots. """
         if '__slots__' not in self.locals:
-            return
+            return None
         for slots in self.igetattr('__slots__'):
             # check if __slots__ is a valid type
             for meth in ITER_METHODS:
@@ -2558,6 +2558,8 @@ class ClassDef(mixins.FilterStmtsMixin, LocalsDictNodeNG,
                 except exceptions.InferenceError:
                     continue
 
+        return None
+
     def _slots(self):
         if not self.newstyle:
             raise NotImplementedError(