From: Pablo Galindo <Pablogsal@gmail.com>
Date: Mon, 23 Dec 2019 16:42:48 +0000 (+0000)
Subject: Revert "bpo-38870: Remove dependency on contextlib to avoid performance regression... 
X-Git-Tag: v3.9.0a3~197
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d69cbeb99d5fd0d5464e937202cca6a2024d1bcf;p=thirdparty%2FPython%2Fcpython.git

Revert "bpo-38870: Remove dependency on contextlib to avoid performance regression on import (GH-17376)" (GH-17687)

This reverts commit ded8888fbc33011dd39b7b1c86a5adfacc4943f3.
---

diff --git a/Lib/ast.py b/Lib/ast.py
index 76e0cac838b9..62f6e075a09f 100644
--- a/Lib/ast.py
+++ b/Lib/ast.py
@@ -597,22 +597,15 @@ class _Unparser(NodeVisitor):
         self._buffer.clear()
         return value
 
-    class _Block:
+    @contextmanager
+    def block(self):
         """A context manager for preparing the source for blocks. It adds
         the character':', increases the indentation on enter and decreases
         the indentation on exit."""
-        def __init__(self, unparser):
-            self.unparser = unparser
-
-        def __enter__(self):
-            self.unparser.write(":")
-            self.unparser._indent += 1
-
-        def __exit__(self, exc_type, exc_value, traceback):
-            self.unparser._indent -= 1
-
-    def block(self):
-        return self._Block(self)
+        self.write(":")
+        self._indent += 1
+        yield
+        self._indent -= 1
 
     @contextmanager
     def delimit(self, start, end):