From 314cb9ffd369b5ab99688c885eb537c901e861eb Mon Sep 17 00:00:00 2001
From: Nick Drozd <nicholasdrozd@gmail.com>
Date: Sat, 18 Sep 2021 10:42:49 -0500
Subject: Use node_ancestors to get rid of some while-loops (#5005)

* Use node_ancestors method

* Rename loop variables
---
 .gitignore                                         |  1 +
 pylint/checkers/base.py                            | 19 +++++++------------
 pylint/checkers/refactoring/refactoring_checker.py |  6 +++---
 pylint/checkers/utils.py                           | 18 +++++-------------
 4 files changed, 16 insertions(+), 28 deletions(-)

diff --git a/.gitignore b/.gitignore
index 3d96061c6..046061c9b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -19,3 +19,4 @@ build-stamp
 .eggs/
 .pytest_cache/
 .mypy_cache/
+.benchmarks/
diff --git a/pylint/checkers/base.py b/pylint/checkers/base.py
index 68f6bd59d..4578fbc5b 100644
--- a/pylint/checkers/base.py
+++ b/pylint/checkers/base.py
@@ -238,8 +238,7 @@ def _redefines_import(node):
 
 def in_loop(node):
     """return True if the node is inside a kind of for loop"""
-    parent = node.parent
-    while parent is not None:
+    for parent in node.node_ancestors():
         if isinstance(
             parent,
             (
@@ -251,7 +250,6 @@ def in_loop(node):
             ),
         ):
             return True
-        parent = parent.parent
     return False
 
 
@@ -847,23 +845,20 @@ class BasicErrorChecker(_BasicChecker):
 
     def _check_in_loop(self, node, node_name):
         """check that a node is inside a for or while loop"""
-        _node = node.parent
-        while _node:
-            if isinstance(_node, (nodes.For, nodes.While)):
-                if node not in _node.orelse:
+        for parent in node.node_ancestors():
+            if isinstance(parent, (nodes.For, nodes.While)):
+                if node not in parent.orelse:
                     return
 
-            if isinstance(_node, (nodes.ClassDef, nodes.FunctionDef)):
+            if isinstance(parent, (nodes.ClassDef, nodes.FunctionDef)):
                 break
             if (
-                isinstance(_node, nodes.TryFinally)
-                and node in _node.finalbody
+                isinstance(parent, nodes.TryFinally)
+                and node in parent.finalbody
                 and isinstance(node, nodes.Continue)
             ):
                 self.add_message("continue-in-finally", node=node)
 
-            _node = _node.parent
-
         self.add_message("not-in-loop", node=node, args=node_name)
 
     def _check_redefinition(self, redeftype, node):
diff --git a/pylint/checkers/refactoring/refactoring_checker.py b/pylint/checkers/refactoring/refactoring_checker.py
index 02b28eb52..c90e550d2 100644
--- a/pylint/checkers/refactoring/refactoring_checker.py
+++ b/pylint/checkers/refactoring/refactoring_checker.py
@@ -116,11 +116,11 @@ def _is_inside_context_manager(node: nodes.Call) -> bool:
 
 def _is_a_return_statement(node: nodes.Call) -> bool:
     frame = node.frame()
-    parent = node.parent
-    while parent is not frame:
+    for parent in node.node_ancestors():
+        if parent is frame:
+            break
         if isinstance(parent, nodes.Return):
             return True
-        parent = parent.parent
     return False
 
 
diff --git a/pylint/checkers/utils.py b/pylint/checkers/utils.py
index e6e91c2c1..305a4fc94 100644
--- a/pylint/checkers/utils.py
+++ b/pylint/checkers/utils.py
@@ -275,11 +275,9 @@ class InferredTypeError(Exception):
 
 def is_inside_lambda(node: nodes.NodeNG) -> bool:
     """Return true if given node is inside lambda"""
-    parent = node.parent
-    while parent is not None:
+    for parent in node.node_ancestors():
         if isinstance(parent, nodes.Lambda):
             return True
-        parent = parent.parent
     return False
 
 
@@ -377,11 +375,9 @@ def is_defined_before(var_node: nodes.Name) -> bool:
     (statement_defining ; statement_using).
     """
     varname = var_node.name
-    _node = var_node.parent
-    while _node:
-        if is_defined_in_scope(var_node, varname, _node):
+    for parent in var_node.node_ancestors():
+        if is_defined_in_scope(var_node, varname, parent):
             return True
-        _node = _node.parent
     # possibly multiple statements on the same line using semi colon separator
     stmt = var_node.statement()
     _node = stmt.previous_sibling()
@@ -415,8 +411,7 @@ def is_default_argument(
 
 def is_func_decorator(node: nodes.NodeNG) -> bool:
     """return true if the name is used in function decorator"""
-    parent = node.parent
-    while parent is not None:
+    for parent in node.node_ancestors():
         if isinstance(parent, nodes.Decorators):
             return True
         if parent.is_statement or isinstance(
@@ -428,7 +423,6 @@ def is_func_decorator(node: nodes.NodeNG) -> bool:
             ),
         ):
             break
-        parent = parent.parent
     return False
 
 
@@ -909,9 +903,7 @@ def find_except_wrapper_node_in_scope(
     node: nodes.NodeNG,
 ) -> Optional[Union[nodes.ExceptHandler, nodes.TryExcept]]:
     """Return the ExceptHandler in which the node is, without going out of scope."""
-    current = node
-    while current.parent is not None:
-        current = current.parent
+    for current in node.node_ancestors():
         if isinstance(current, astroid.scoped_nodes.LocalsDictNodeNG):
             # If we're inside a function/class definition, we don't want to keep checking
             # higher ancestors for `except` clauses, because if these exist, it means our
-- 
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