Fix some scripts in the peg generator folder (GH-19853)

Lib/test/test_peg_generator/ast_dump.py

@@ -1,62 +0,0 @@
-"""
-Copy-parse of ast.dump, removing the `isinstance` checks. This is needed,
-because testing pegen requires generating a C extension module, which contains
-a copy of the symbols defined in Python-ast.c. Thus, the isinstance check would
-always fail. We rely on string comparison of the base classes instead.
-TODO: Remove the above-described hack.
-"""
-
-def ast_dump(node, annotate_fields=True, include_attributes=False, *, indent=None):
-    def _format(node, level=0):
-        if indent is not None:
-            level += 1
-            prefix = '\n' + indent * level
-            sep = ',\n' + indent * level
-        else:
-            prefix = ''
-            sep = ', '
-        if any(cls.__name__ == 'AST' for cls in node.__class__.__mro__):
-            cls = type(node)
-            args = []
-            allsimple = True
-            keywords = annotate_fields
-            for name in node._fields:
-                try:
-                    value = getattr(node, name)
-                except AttributeError:
-                    keywords = True
-                    continue
-                if value is None and getattr(cls, name, ...) is None:
-                    keywords = True
-                    continue
-                value, simple = _format(value, level)
-                allsimple = allsimple and simple
-                if keywords:
-                    args.append('%s=%s' % (name, value))
-                else:
-                    args.append(value)
-            if include_attributes and node._attributes:
-                for name in node._attributes:
-                    try:
-                        value = getattr(node, name)
-                    except AttributeError:
-                        continue
-                    if value is None and getattr(cls, name, ...) is None:
-                        continue
-                    value, simple = _format(value, level)
-                    allsimple = allsimple and simple
-                    args.append('%s=%s' % (name, value))
-            if allsimple and len(args) <= 3:
-                return '%s(%s)' % (node.__class__.__name__, ', '.join(args)), not args
-            return '%s(%s%s)' % (node.__class__.__name__, prefix, sep.join(args)), False
-        elif isinstance(node, list):
-            if not node:
-                return '[]', True
-            return '[%s%s]' % (prefix, sep.join(_format(x, level)[0] for x in node)), False
-        return repr(node), True
-
-    if all(cls.__name__ != 'AST' for cls in node.__class__.__mro__):
-        raise TypeError('expected AST, got %r' % node.__class__.__name__)
-    if indent is not None and not isinstance(indent, str):
-        indent = ' ' * indent
-    return _format(node)[0]

Lib/test/test_peg_generator/test_c_parser.py

@@ -15,6 +15,7 @@ with test_tools.imports_under_tool("peg_generator"):
         generate_parser_c_extension,
         generate_c_parser_source,
     )
+    from pegen.ast_dump import ast_dump
 
 
 TEST_TEMPLATE = """
@@ -24,7 +25,10 @@ import ast
 import traceback
 import sys
 import unittest
-from test.test_peg_generator.ast_dump import ast_dump
+
+from test import test_tools
+with test_tools.imports_under_tool("peg_generator"):
+    from pegen.ast_dump import ast_dump
 
 sys.path.insert(0, tmp_dir)
 import parse