diff options
Diffstat (limited to 'Lib/test')
| -rw-r--r-- | Lib/test/test_generators.py | 12 | ||||
| -rw-r--r-- | Lib/test/test_grammar.py | 35 |
2 files changed, 36 insertions, 11 deletions
diff --git a/Lib/test/test_generators.py b/Lib/test/test_generators.py index 7eac9d0..f88c762 100644 --- a/Lib/test/test_generators.py +++ b/Lib/test/test_generators.py @@ -1830,13 +1830,7 @@ Yield by itself yields None: [None] - -An obscene abuse of a yield expression within a generator expression: - ->>> list((yield 21) for i in range(4)) -[21, None, 21, None, 21, None, 21, None] - -And a more sane, but still weird usage: +Yield is allowed only in the outermost iterable in generator expression: >>> def f(): list(i for i in [(yield 26)]) >>> type(f()) @@ -2106,10 +2100,6 @@ enclosing function a generator: >>> type(f()) <class 'generator'> ->>> def f(): x=(i for i in (yield) if (yield)) ->>> type(f()) -<class 'generator'> - >>> def f(d): d[(yield "a")] = d[(yield "b")] = 27 >>> data = [1,2] >>> g = f(data) diff --git a/Lib/test/test_grammar.py b/Lib/test/test_grammar.py index 65e26bf..823315f 100644 --- a/Lib/test/test_grammar.py +++ b/Lib/test/test_grammar.py @@ -841,6 +841,41 @@ class GrammarTests(unittest.TestCase): # Check annotation refleak on SyntaxError check_syntax_error(self, "def g(a:(yield)): pass") + def test_yield_in_comprehensions(self): + # Check yield in comprehensions + def g(): [x for x in [(yield 1)]] + def g(): [x for x in [(yield from ())]] + + def check(code, warntext): + with self.assertWarnsRegex(DeprecationWarning, warntext): + compile(code, '<test string>', 'exec') + import warnings + with warnings.catch_warnings(): + warnings.filterwarnings('error', category=DeprecationWarning) + with self.assertRaisesRegex(SyntaxError, warntext): + compile(code, '<test string>', 'exec') + + check("def g(): [(yield x) for x in ()]", + "'yield' inside list comprehension") + check("def g(): [x for x in () if not (yield x)]", + "'yield' inside list comprehension") + check("def g(): [y for x in () for y in [(yield x)]]", + "'yield' inside list comprehension") + check("def g(): {(yield x) for x in ()}", + "'yield' inside set comprehension") + check("def g(): {(yield x): x for x in ()}", + "'yield' inside dict comprehension") + check("def g(): {x: (yield x) for x in ()}", + "'yield' inside dict comprehension") + check("def g(): ((yield x) for x in ())", + "'yield' inside generator expression") + check("def g(): [(yield from x) for x in ()]", + "'yield' inside list comprehension") + check("class C: [(yield x) for x in ()]", + "'yield' inside list comprehension") + check("[(yield x) for x in ()]", + "'yield' inside list comprehension") + def test_raise(self): # 'raise' test [',' test] try: raise RuntimeError('just testing') |