gh-145239: Accept unary plus literal pattern

Doc/reference/compound_stmts.rst

@@ -858,7 +858,7 @@ A literal pattern corresponds to most
  : | "None"
  : | "True"
  : | "False"
- signed_number: ["-"] NUMBER
+ signed_number: ["+" | "-"] NUMBER
 
 The rule ``strings`` and the token ``NUMBER`` are defined in the
 :doc:`standard Python grammar <./grammar>`. Triple-quoted strings are

Doc/whatsnew/3.15.rst

@@ -608,6 +608,10 @@ Other language changes
 * Allow the *count* argument of :meth:`bytes.replace` to be a keyword.
  (Contributed by Stan Ulbrych in :gh:`147856`.)
 
+* Unary plus is now accepted in :keyword:`match` literal patterns, mirroring
+ the existing support for unary minus.
+ (Contributed by Bartosz Sławecki in :gh:`145239`.)
+
 
 New modules
 ===========

Grammar/python.gram

@@ -554,17 +554,20 @@ complex_number[expr_ty]:
 
 signed_number[expr_ty]:
  | NUMBER
+ | '+' number=NUMBER { number }
  | '-' number=NUMBER { _PyAST_UnaryOp(USub, number, EXTRA) }
 
 signed_real_number[expr_ty]:
  | real_number
+ | '+' real=real_number { real }
  | '-' real=real_number { _PyAST_UnaryOp(USub, real, EXTRA) }
 
 real_number[expr_ty]:
  | real=NUMBER { _PyPegen_ensure_real(p, real) }
 
 imaginary_number[expr_ty]:
  | imag=NUMBER { _PyPegen_ensure_imaginary(p, imag) }
+ | '+' imag=NUMBER { _PyPegen_ensure_imaginary(p, imag) }
 
 capture_pattern[pattern_ty]:
  | target=pattern_capture_target { _PyAST_MatchAs(NULL, target->v.Name.id, EXTRA) }

Lib/test/.ruff.toml

@@ -18,6 +18,8 @@ extend-exclude = [
  "test_lazy_import/__init__.py",
  "test_lazy_import/data/*.py",
  "test_lazy_import/data/**/*.py",
+ # Unary plus literal pattern is not yet supported by Ruff (GH-145239)
+ "test_patma.py",
 ]
 
 [lint]

Lib/test/test_patma.py

@@ -2762,6 +2762,96 @@ def test_patma_255(self):
  self.assertEqual(y, 1)
  self.assertIs(z, x)
 
+ def test_patma_256(self):
+ x = 0
+ match x:
+ case +0:
+ y = 0
+ self.assertEqual(x, 0)
+ self.assertEqual(y, 0)
+
+ def test_patma_257(self):
+ x = 0
+ match x:
+ case +0.0:
+ y = 0
+ self.assertEqual(x, 0)
+ self.assertEqual(y, 0)
+
+ def test_patma_258(self):
+ x = 0
+ match x:
+ case +0j:
+ y = 0
+ self.assertEqual(x, 0)
+ self.assertEqual(y, 0)
+
+ def test_patma_259(self):
+ x = 0
+ match x:
+ case +0.0j:
+ y = 0
+ self.assertEqual(x, 0)
+ self.assertEqual(y, 0)
+
+ def test_patma_260(self):
+ x = 1
+ match x:
+ case +1:
+ y = 0
+ self.assertEqual(x, 1)
+ self.assertEqual(y, 0)
+
+ def test_patma_261(self):
+ x = 1.5
+ match x:
+ case +1.5:
+ y = 0
+ self.assertEqual(x, 1.5)
+ self.assertEqual(y, 0)
+
+ def test_patma_262(self):
+ x = 1j
+ match x:
+ case +1j:
+ y = 0
+ self.assertEqual(x, 1j)
+ self.assertEqual(y, 0)
+
+ def test_patma_263(self):
+ x = 1.5j
+ match x:
+ case +1.5j:
+ y = 0
+ self.assertEqual(x, 1.5j)
+ self.assertEqual(y, 0)
+
+ def test_patma_264(self):
+ x = 0.25 + 1.75j
+ match x:
+ case +0.25 + 1.75j:
+ y = 0
+ self.assertEqual(x, 0.25 + 1.75j)
+ self.assertEqual(y, 0)
+
+ def test_patma_265(self):
+ x = 0.25 - 1.75j
+ match x:
+ case 0.25 - +1.75j:
+ y = 0
+ self.assertEqual(x, 0.25 - 1.75j)
+ self.assertEqual(y, 0)
+
+ def test_patma_266(self):
+ x = 0
+ match x:
+ case +1e1000:
+ y = 0
+ case 0:
+ y = 1
+ self.assertEqual(x, 0)
+ self.assertEqual(y, 1)
+
  def test_patma_runtime_checkable_protocol(self):
  # Runtime-checkable protocol
  from typing import Protocol, runtime_checkable

Misc/NEWS.d/next/Core_and_Builtins/2026-04-13-23-21-45.gh-issue-145239.pL8qRt.rst

@@ -0,0 +1,3 @@
+Unary plus is now accepted in :keyword:`match` literal patterns, mirroring
+the existing support for unary minus.
+Patch by Bartosz Sławecki.