Move builtin_lookup out of main scoped_nodes file (#1460)

Co-authored-by: Marc Mueller <[email protected]>

Author: DanielNoord

astroid/nodes/scoped_nodes/__init__.py

@@ -19,10 +19,10 @@
     Module,
     SetComp,
     _is_metaclass,
-    builtin_lookup,
     function_to_method,
     get_wrapping_class,
 )
+from astroid.nodes.scoped_nodes.utils import builtin_lookup
 
 __all__ = (
     "AsyncFunctionDef",

astroid/nodes/scoped_nodes/scoped_nodes.py

@@ -45,7 +45,6 @@
 new local scope in the language definition : Module, ClassDef, FunctionDef (and
 Lambda, GeneratorExp, DictComp and SetComp to some extent).
 """
-import builtins
 import io
 import itertools
 import os
@@ -80,6 +79,7 @@
 from astroid.interpreter.objectmodel import ClassModel, FunctionModel, ModuleModel
 from astroid.manager import AstroidManager
 from astroid.nodes import Arguments, Const, node_classes
+from astroid.nodes.scoped_nodes.utils import builtin_lookup
 from astroid.nodes.utils import Position
 
 if sys.version_info >= (3, 6, 2):
@@ -215,21 +215,6 @@ def function_to_method(n, klass):
     return n
 
 
-def builtin_lookup(name):
-    """lookup a name into the builtin module
-    return the list of matching statements and the astroid for the builtin
-    module
-    """
-    builtin_astroid = AstroidManager().ast_from_module(builtins)
-    if name == "__dict__":
-        return builtin_astroid, ()
-    try:
-        stmts = builtin_astroid.locals[name]
-    except KeyError:
-        stmts = ()
-    return builtin_astroid, stmts
-
-
 # TODO move this Mixin to mixins.py; problem: 'FunctionDef' in _scope_lookup
 class LocalsDictNodeNG(node_classes.LookupMixIn, node_classes.NodeNG):
     """this class provides locals handling common to Module, FunctionDef

astroid/nodes/scoped_nodes/utils.py

@@ -0,0 +1,35 @@
+# Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html
+# For details: https://github.com/PyCQA/astroid/blob/main/LICENSE
+
+"""
+This module contains utility functions for scoped nodes.
+"""
+
+import builtins
+from typing import TYPE_CHECKING, Sequence, Tuple
+
+from astroid.manager import AstroidManager
+
+if TYPE_CHECKING:
+    from astroid import nodes
+
+
+_builtin_astroid: "nodes.Module | None" = None
+
+
+def builtin_lookup(name: str) -> Tuple["nodes.Module", Sequence["nodes.NodeNG"]]:
+    """Lookup a name in the builtin module.
+
+    Return the list of matching statements and the ast for the builtin module
+    """
+    # pylint: disable-next=global-statement
+    global _builtin_astroid
+    if _builtin_astroid is None:
+        _builtin_astroid = AstroidManager().ast_from_module(builtins)
+    if name == "__dict__":
+        return _builtin_astroid, ()
+    try:
+        stmts: Sequence["nodes.NodeNG"] = _builtin_astroid.locals[name]
+    except KeyError:
+        stmts = ()
+    return _builtin_astroid, stmts