bpo-38605: Make 'from __future__ import annotations' the default (GH-20434)

The hard part was making all the tests pass; there are some subtle issues here, because apparently the future import wasn't tested very thoroughly in previous Python versions.

For example, `inspect.signature()` returned type objects normally (except for forward references), but strings with the future import. We changed it to try and return type objects by calling `typing.get_type_hints()`, but fall back on returning strings if that function fails (which it may do if there are future references in the annotations that require passing in a specific namespace to resolve).
This commit is contained in:
Batuhan Taskaya 2020-10-06 23:03:02 +03:00 committed by GitHub
parent bef7d299eb
commit 044a1048ca
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GPG key ID: 4AEE18F83AFDEB23
27 changed files with 403 additions and 299 deletions

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@ -862,7 +862,7 @@ class TestClassesAndFunctions(unittest.TestCase):
self.assertFullArgSpecEquals(mod2.annotated, ['arg1'],
ann_e={'arg1' : list},
formatted='(arg1: list)')
formatted="(arg1: list)")
self.assertFullArgSpecEquals(mod2.keyword_only_arg, [],
kwonlyargs_e=['arg'],
formatted='(*, arg)')
@ -2211,8 +2211,8 @@ class TestSignatureObject(unittest.TestCase):
pass
self.assertEqual(self.signature(test),
((('a', ..., ..., "positional_or_keyword"),
('b', ..., 'foo', "positional_or_keyword")),
123))
('b', ..., repr('foo'), "positional_or_keyword")),
'123'))
def test_signature_on_wkwonly(self):
def test(*, a:float, b:str) -> int:
@ -2227,11 +2227,11 @@ class TestSignatureObject(unittest.TestCase):
pass
self.assertEqual(self.signature(test),
((('a', ..., ..., "positional_or_keyword"),
('b', 10, 'foo', "positional_or_keyword"),
('args', ..., 'bar', "var_positional"),
('spam', ..., 'baz', "keyword_only"),
('b', 10, repr('foo'), "positional_or_keyword"),
('args', ..., repr('bar'), "var_positional"),
('spam', ..., repr('baz'), "keyword_only"),
('ham', 123, ..., "keyword_only"),
('kwargs', ..., int, "var_keyword")),
('kwargs', ..., 'int', "var_keyword")),
...))
def test_signature_without_self(self):
@ -2640,12 +2640,12 @@ class TestSignatureObject(unittest.TestCase):
self.assertEqual(self.signature(partial(partial(test, 1))),
((('b', ..., ..., "positional_or_keyword"),
('c', ..., int, "positional_or_keyword")),
42))
('c', ..., 'int', "positional_or_keyword")),
'42'))
self.assertEqual(self.signature(partial(partial(test, 1), 2)),
((('c', ..., int, "positional_or_keyword"),),
42))
((('c', ..., 'int', "positional_or_keyword"),),
'42'))
psig = inspect.signature(partial(partial(test, 1), 2))
@ -2764,12 +2764,12 @@ class TestSignatureObject(unittest.TestCase):
((('it', ..., ..., 'positional_or_keyword'),
('a', ..., ..., 'positional_or_keyword'),
('c', 1, ..., 'keyword_only')),
'spam'))
repr('spam')))
self.assertEqual(self.signature(Spam().ham),
((('a', ..., ..., 'positional_or_keyword'),
('c', 1, ..., 'keyword_only')),
'spam'))
repr('spam')))
class Spam:
def test(self: 'anno', x):
@ -2778,7 +2778,7 @@ class TestSignatureObject(unittest.TestCase):
g = partialmethod(test, 1)
self.assertEqual(self.signature(Spam.g),
((('self', ..., 'anno', 'positional_or_keyword'),),
((('self', ..., repr('anno'), 'positional_or_keyword'),),
...))
def test_signature_on_fake_partialmethod(self):
@ -3116,20 +3116,16 @@ class TestSignatureObject(unittest.TestCase):
with self.assertRaisesRegex(TypeError, 'unhashable type'):
hash(inspect.signature(foo))
def foo(a) -> {}: pass
with self.assertRaisesRegex(TypeError, 'unhashable type'):
hash(inspect.signature(foo))
def test_signature_str(self):
def foo(a:int=1, *, b, c=None, **kwargs) -> 42:
pass
self.assertEqual(str(inspect.signature(foo)),
'(a: int = 1, *, b, c=None, **kwargs) -> 42')
'(a: \'int\' = 1, *, b, c=None, **kwargs) -> \'42\'')
def foo(a:int=1, *args, b, c=None, **kwargs) -> 42:
pass
self.assertEqual(str(inspect.signature(foo)),
'(a: int = 1, *args, b, c=None, **kwargs) -> 42')
'(a: \'int\' = 1, *args, b, c=None, **kwargs) -> \'42\'')
def foo():
pass
@ -3172,8 +3168,8 @@ class TestSignatureObject(unittest.TestCase):
self.assertIs(sig.return_annotation, None)
sig = sig.replace(return_annotation=sig.empty)
self.assertIs(sig.return_annotation, sig.empty)
sig = sig.replace(return_annotation=42)
self.assertEqual(sig.return_annotation, 42)
sig = sig.replace(return_annotation='42')
self.assertEqual(sig.return_annotation, '42')
self.assertEqual(sig, inspect.signature(test))
def test_signature_on_mangled_parameters(self):
@ -3185,8 +3181,8 @@ class TestSignatureObject(unittest.TestCase):
self.assertEqual(self.signature(Spam.foo),
((('self', ..., ..., "positional_or_keyword"),
('_Spam__p1', 2, 1, "positional_or_keyword"),
('_Spam__p2', 3, 2, "keyword_only")),
('_Spam__p1', 2, '1', "positional_or_keyword"),
('_Spam__p2', 3, '2', "keyword_only")),
...))
self.assertEqual(self.signature(Spam.foo),