diff options
| -rw-r--r-- | Lib/subprocess.py | 24 | ||||
| -rw-r--r-- | Lib/test/test_subprocess.py | 3 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Library/2019-12-10-21-03-34.bpo-39019.i8RpMZ.rst | 2 |
3 files changed, 29 insertions, 0 deletions
diff --git a/Lib/subprocess.py b/Lib/subprocess.py index ba6f198..30f0d1b 100644 --- a/Lib/subprocess.py +++ b/Lib/subprocess.py @@ -446,6 +446,19 @@ class CompletedProcess(object): args.append('stderr={!r}'.format(self.stderr)) return "{}({})".format(type(self).__name__, ', '.join(args)) + def __class_getitem__(cls, type): + """Provide minimal support for using this class as generic + (for example in type annotations). + + See PEP 484 and PEP 560 for more details. For example, + `CompletedProcess[bytes]` is a valid expression at runtime + (type argument `bytes` indicates the type used for stdout). + Note, no type checking happens at runtime, but a static type + checker can be used. + """ + return cls + + def check_returncode(self): """Raise CalledProcessError if the exit code is non-zero.""" if self.returncode: @@ -987,6 +1000,17 @@ class Popen(object): obj_repr = obj_repr[:76] + "...>" return obj_repr + def __class_getitem__(cls, type): + """Provide minimal support for using this class as generic + (for example in type annotations). + + See PEP 484 and PEP 560 for more details. For example, `Popen[bytes]` + is a valid expression at runtime (type argument `bytes` indicates the + type used for stdout). Note, no type checking happens at runtime, but + a static type checker can be used. + """ + return cls + @property def universal_newlines(self): # universal_newlines as retained as an alias of text_mode for API diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py index 87322c6..2073fd1 100644 --- a/Lib/test/test_subprocess.py +++ b/Lib/test/test_subprocess.py @@ -1435,6 +1435,9 @@ class ProcessTestCase(BaseTestCase): subprocess.Popen(['exit', '0'], cwd='/some/nonexistent/directory') self.assertEqual(c.exception.filename, '/some/nonexistent/directory') + def test_class_getitems(self): + self.assertIs(subprocess.Popen[bytes], subprocess.Popen) + self.assertIs(subprocess.CompletedProcess[str], subprocess.CompletedProcess) class RunFuncTestCase(BaseTestCase): def run_python(self, code, **kwargs): diff --git a/Misc/NEWS.d/next/Library/2019-12-10-21-03-34.bpo-39019.i8RpMZ.rst b/Misc/NEWS.d/next/Library/2019-12-10-21-03-34.bpo-39019.i8RpMZ.rst new file mode 100644 index 0000000..b64a56e --- /dev/null +++ b/Misc/NEWS.d/next/Library/2019-12-10-21-03-34.bpo-39019.i8RpMZ.rst @@ -0,0 +1,2 @@ +Implement dummy ``__class_getitem__`` for ``subprocess.Popen``, +``subprocess.CompletedProcess`` |