https://github.com/python/cpython/commit/ed0e63fd0abcbb68a384f8b5baccf616a5534570 commit: ed0e63fd0abcbb68a384f8b5baccf616a5534570 branch: 3.14 author: Miss Islington (bot) <[email protected]> committer: JelleZijlstra <[email protected]> date: 2025-10-07T21:23:22-07:00 summary:
[3.14] gh-138558: Improve handling of Template annotations in annotationlib (GH-139072) (#139272) gh-138558: Improve handling of Template annotations in annotationlib (GH-139072) (cherry picked from commit 6ec058a1f7fcc016fa3b7432bcd0aa6e7d2b21ce) Co-authored-by: Dave Peck <[email protected]> files: A Misc/NEWS.d/next/Core_and_Builtins/2025-09-17-17-17-21.gh-issue-138558.0VbzCH.rst M Lib/annotationlib.py M Lib/test/test_annotationlib.py diff --git a/Lib/annotationlib.py b/Lib/annotationlib.py index bee019cd51591e..43e1d51bc4b807 100644 --- a/Lib/annotationlib.py +++ b/Lib/annotationlib.py @@ -560,32 +560,70 @@ def unary_op(self): del _make_unary_op -def _template_to_ast(template): +def _template_to_ast_constructor(template): + """Convert a `template` instance to a non-literal AST.""" + args = [] + for part in template: + match part: + case str(): + args.append(ast.Constant(value=part)) + case _: + interp = ast.Call( + func=ast.Name(id="Interpolation"), + args=[ + ast.Constant(value=part.value), + ast.Constant(value=part.expression), + ast.Constant(value=part.conversion), + ast.Constant(value=part.format_spec), + ] + ) + args.append(interp) + return ast.Call(func=ast.Name(id="Template"), args=args, keywords=[]) + + +def _template_to_ast_literal(template, parsed): + """Convert a `template` instance to a t-string literal AST.""" values = [] + interp_count = 0 for part in template: match part: case str(): values.append(ast.Constant(value=part)) - # Interpolation, but we don't want to import the string module case _: interp = ast.Interpolation( str=part.expression, - value=ast.parse(part.expression), - conversion=( - ord(part.conversion) - if part.conversion is not None - else -1 - ), - format_spec=( - ast.Constant(value=part.format_spec) - if part.format_spec != "" - else None - ), + value=parsed[interp_count], + conversion=ord(part.conversion) if part.conversion else -1, + format_spec=ast.Constant(value=part.format_spec) + if part.format_spec + else None, ) values.append(interp) + interp_count += 1 return ast.TemplateStr(values=values) +def _template_to_ast(template): + """Make a best-effort conversion of a `template` instance to an AST.""" + # gh-138558: Not all Template instances can be represented as t-string + # literals. Return the most accurate AST we can. See issue for details. + + # If any expr is empty or whitespace only, we cannot convert to a literal. + if any(part.expression.strip() == "" for part in template.interpolations): + return _template_to_ast_constructor(template) + + try: + # Wrap in parens to allow whitespace inside interpolation curly braces + parsed = tuple( + ast.parse(f"({part.expression})", mode="eval").body + for part in template.interpolations + ) + except SyntaxError: + return _template_to_ast_constructor(template) + + return _template_to_ast_literal(template, parsed) + + class _StringifierDict(dict): def __init__(self, namespace, *, globals=None, owner=None, is_class=False, format): super().__init__(namespace) diff --git a/Lib/test/test_annotationlib.py b/Lib/test/test_annotationlib.py index 88e0d611647f28..a8a8bcec76a429 100644 --- a/Lib/test/test_annotationlib.py +++ b/Lib/test/test_annotationlib.py @@ -7,7 +7,7 @@ import functools import itertools import pickle -from string.templatelib import Template +from string.templatelib import Template, Interpolation import typing import unittest from annotationlib import ( @@ -282,6 +282,7 @@ def f( a: t"a{b}c{d}e{f}g", b: t"{a:{1}}", c: t"{a | b * c}", + gh138558: t"{ 0}", ): pass annos = get_annotations(f, format=Format.STRING) @@ -293,6 +294,7 @@ def f( # interpolations in the format spec are eagerly evaluated so we can't recover the source "b": "t'{a:1}'", "c": "t'{a | b * c}'", + "gh138558": "t'{ 0}'", }) def g( @@ -1350,6 +1352,24 @@ def nested(): self.assertEqual(type_repr("1"), "'1'") self.assertEqual(type_repr(Format.VALUE), repr(Format.VALUE)) self.assertEqual(type_repr(MyClass()), "my repr") + # gh138558 tests + self.assertEqual(type_repr(t'''{ 0 + & 1 + | 2 + }'''), 't"""{ 0\n & 1\n | 2}"""') + self.assertEqual( + type_repr(Template("hi", Interpolation(42, "42"))), "t'hi{42}'" + ) + self.assertEqual( + type_repr(Template("hi", Interpolation(42))), + "Template('hi', Interpolation(42, '', None, ''))", + ) + self.assertEqual( + type_repr(Template("hi", Interpolation(42, " "))), + "Template('hi', Interpolation(42, ' ', None, ''))", + ) + # gh138558: perhaps in the future, we can improve this behavior: + self.assertEqual(type_repr(Template(Interpolation(42, "99"))), "t'{99}'") class TestAnnotationsToString(unittest.TestCase): diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-09-17-17-17-21.gh-issue-138558.0VbzCH.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-09-17-17-17-21.gh-issue-138558.0VbzCH.rst new file mode 100644 index 00000000000000..23c995d2452f7b --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-09-17-17-17-21.gh-issue-138558.0VbzCH.rst @@ -0,0 +1 @@ +Fix handling of unusual t-string annotations in annotationlib. Patch by Dave Peck. _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
