ruff/crates/ruff_python_formatter/src/other
Brent Westbrook 591e9bbccb
Remove parentheses around multiple exception types on Python 3.14+ (#20768)
Summary
--

This PR implements the black preview style from
https://github.com/psf/black/pull/4720. As of Python 3.14, you're
allowed to omit the parentheses around groups of exceptions, as long as
there's no `as` binding:

**3.13**

```pycon
Python 3.13.4 (main, Jun  4 2025, 17:37:06) [Clang 20.1.4 ] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> try: ...
... except (Exception, BaseException): ...
...
Ellipsis
>>> try: ...
... except Exception, BaseException: ...
...
  File "<python-input-1>", line 2
    except Exception, BaseException: ...
           ^^^^^^^^^^^^^^^^^^^^^^^^
SyntaxError: multiple exception types must be parenthesized
```

**3.14**

```pycon
Python 3.14.0rc2 (main, Sep  2 2025, 14:20:56) [Clang 20.1.4 ] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> try: ...
... except Exception, BaseException: ...
...
Ellipsis
>>> try: ...
... except (Exception, BaseException): ...
...
Ellipsis
>>> try: ...
... except Exception, BaseException as e: ...
...
  File "<python-input-2>", line 2
    except Exception, BaseException as e: ...
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
SyntaxError: multiple exception types must be parenthesized when using 'as'
```

I think this ended up being pretty straightforward, at least once Micha
showed me where to start :)

Test Plan
--

New tests

At first I thought we were deviating from black in how we handle
comments within the exception type tuple, but I think this applies to
how we format all tuples, not specifically with the new preview style.
2025-10-14 11:17:45 -04:00
..
alias.rs [ruff] improve handling of intermixed comments inside from-imports (#20561) 2025-10-07 08:14:09 -07:00
arguments.rs [ty] AST garbage collection (#18482) 2025-06-13 08:40:11 -04:00
bytes_literal.rs Remove layout values from `AnyStringPart` (#13681) 2024-10-09 07:25:40 +01:00
commas.rs Switch to Rust 2024 edition (#18129) 2025-05-16 13:25:28 +02:00
comprehension.rs [ty] AST garbage collection (#18482) 2025-06-13 08:40:11 -04:00
decorator.rs [ty] AST garbage collection (#18482) 2025-06-13 08:40:11 -04:00
elif_else_clause.rs Insert empty line between suite and alternative branch after def/class (#12294) 2024-07-15 12:59:33 +02:00
except_handler_except_handler.rs Remove parentheses around multiple exception types on Python 3.14+ (#20768) 2025-10-14 11:17:45 -04:00
f_string.rs Implement template strings (#17851) 2025-05-30 15:00:56 -05:00
identifier.rs Range formatting: Fix invalid syntax after parenthesizing expression (#9751) 2024-02-02 17:56:25 +01:00
interpolated_string.rs Hug closing `}` when f-string expression has a format specifier (#18704) 2025-06-17 07:39:42 +02:00
interpolated_string_element.rs Disallow newlines in format specifiers of single quoted f- or t-strings (#18708) 2025-06-18 14:56:15 +02:00
keyword.rs [ty] AST garbage collection (#18482) 2025-06-13 08:40:11 -04:00
match_case.rs [ty] AST garbage collection (#18482) 2025-06-13 08:40:11 -04:00
mod.rs Implement template strings (#17851) 2025-05-30 15:00:56 -05:00
parameter.rs [ty] AST garbage collection (#18482) 2025-06-13 08:40:11 -04:00
parameter_with_default.rs [ty] AST garbage collection (#18482) 2025-06-13 08:40:11 -04:00
parameters.rs [ty] AST garbage collection (#18482) 2025-06-13 08:40:11 -04:00
string_literal.rs Switch to Rust 2024 edition (#18129) 2025-05-16 13:25:28 +02:00
t_string.rs Implement template strings (#17851) 2025-05-30 15:00:56 -05:00
with_item.rs [ty] AST garbage collection (#18482) 2025-06-13 08:40:11 -04:00