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).

1 files changed, 0 insertions, 8 deletions

diff --git a/Lib/test/test_coroutines.py b/Lib/test/test_coroutines.py
index 145adb6..40c2eb8 100644
--- a/Lib/test/test_coroutines.py
+++ b/Lib/test/test_coroutines.py
@@ -91,10 +91,6 @@ class AsyncBadSyntaxTest(unittest.TestCase):
                 pass
             """,
 
-            """async def foo(a:await something()):
-                pass
-            """,
-
             """async def foo():
                 def bar():
                  [i async for i in els]
@@ -299,10 +295,6 @@ class AsyncBadSyntaxTest(unittest.TestCase):
                    pass
             """,
 
-            """async def foo(a:await b):
-                   pass
-            """,
-
             """def baz():
                    async def foo(a=await b):
                        pass