Move FrozenSet to node_classes so it is accessible

importing astroid.objects causes curcular imports with manager

astroid/brain/brain_builtin_inference.py

@@ -186,7 +186,7 @@ def _infer_builtin(node, context,
 infer_tuple = partial(
     _infer_builtin,
     klass=nodes.Tuple,
-    iterables=(nodes.List, nodes.Set, objects.FrozenSet,
+    iterables=(nodes.List, nodes.Set, nodes.FrozenSet,
                objects.DictItems, objects.DictKeys,
                objects.DictValues),
     build_elts=tuple)
@@ -194,7 +194,7 @@ infer_tuple = partial(
 infer_list = partial(
     _infer_builtin,
     klass=nodes.List,
-    iterables=(nodes.Tuple, nodes.Set, objects.FrozenSet,
+    iterables=(nodes.Tuple, nodes.Set, nodes.FrozenSet,
                objects.DictItems, objects.DictKeys,
                objects.DictValues),
     build_elts=list)
@@ -202,14 +202,14 @@ infer_list = partial(
 infer_set = partial(
     _infer_builtin,
     klass=nodes.Set,
-    iterables=(nodes.List, nodes.Tuple, objects.FrozenSet,
+    iterables=(nodes.List, nodes.Tuple, nodes.FrozenSet,
                objects.DictKeys),
     build_elts=set)
 infer_frozenset = partial(
     _infer_builtin,
-    klass=objects.FrozenSet,
-    iterables=(nodes.List, nodes.Tuple, nodes.Set, objects.FrozenSet,
+    klass=nodes.FrozenSet,
+    iterables=(nodes.List, nodes.Tuple, nodes.Set, nodes.FrozenSet,
                objects.DictKeys),
     build_elts=frozenset)

astroid/node_classes.py

@@ -2837,6 +2837,21 @@ class ExceptHandler(mixins.AssignTypeMixin, Statement):
         return False
+class FrozenSet(_BaseContainer):
+    """class representing a FrozenSet composite node"""
+
+    def pytype(self):
+        return '%s.frozenset' % BUILTINS
+
+    def _infer(self, context=None):
+        yield self
+
+    @decorators.cachedproperty
+    def _proxied(self): # pylint: disable=method-hidden
+        builtins = MANAGER.astroid_cache[BUILTINS]
+        return builtins.getattr('frozenset')[0]
+
+
 class Exec(Statement):
     """Class representing the ``exec`` statement.

astroid/nodes.py

@@ -20,7 +20,7 @@ from astroid.node_classes import (
     AssignName, AugAssign, Repr, BinOp, BoolOp, Break, Call, Compare,
     Comprehension, Const, Continue, Decorators, DelAttr, DelName, Delete,
     Dict, Expr, Ellipsis, EmptyNode, ExceptHandler, Exec, ExtSlice, For,
-    ImportFrom, Attribute, Global, If, IfExp, Import, Index, Keyword,
+    FrozenSet, ImportFrom, Attribute, Global, If, IfExp, Import, Index, Keyword,
     List, Name, Nonlocal, Pass, Print, Raise, Return, Set, Slice, Starred, Subscript,
     TryExcept, TryFinally, Tuple, UnaryOp, While, With, Yield, YieldFrom,
     const_factory,

astroid/objects.py

@@ -29,21 +29,6 @@ BUILTINS = six.moves.builtins.__name__
 objectmodel = util.lazy_import('interpreter.objectmodel')
-class FrozenSet(node_classes._BaseContainer):
-    """class representing a FrozenSet composite node"""
-
-    def pytype(self):
-        return '%s.frozenset' % BUILTINS
-
-    def _infer(self, context=None):
-        yield self
-
-    @decorators.cachedproperty
-    def _proxied(self): # pylint: disable=method-hidden
-        builtins = MANAGER.astroid_cache[BUILTINS]
-        return builtins.getattr('frozenset')[0]
-
-
 class Super(node_classes.NodeNG):
     """Proxy class over a super call.

astroid/tests/unittest_inference.py

@@ -26,7 +26,6 @@ from astroid import arguments
 from astroid import decorators as decoratorsmod
 from astroid import exceptions
 from astroid import helpers
-from astroid import objects
 from astroid import test_utils
 from astroid import util
 from astroid.tests import resources
@@ -89,7 +88,7 @@ class InferenceTest(resources.SysPathSetup, unittest.TestCase):
     assertInferTuple = partialmethod(_assertInferElts, nodes.Tuple)
     assertInferList = partialmethod(_assertInferElts, nodes.List)
     assertInferSet = partialmethod(_assertInferElts, nodes.Set)
-    assertInferFrozenSet = partialmethod(_assertInferElts, objects.FrozenSet)
+    assertInferFrozenSet = partialmethod(_assertInferElts, nodes.FrozenSet)
     CODE = '''
         class C(object):

astroid/tests/unittest_objects.py

@@ -21,7 +21,7 @@ class ObjectsTest(unittest.TestCase):
         frozenset({1: 2, 2: 3}) #@
         """)
         inferred = next(node.infer())
-        self.assertIsInstance(inferred, objects.FrozenSet)
+        self.assertIsInstance(inferred, nodes.FrozenSet)
         self.assertEqual(inferred.pytype(), "%s.frozenset" % bases.BUILTINS)