From 09f3221fbbf72692308149054e4f7668b08b22eb Mon Sep 17 00:00:00 2001 From: Serhiy Storchaka Date: Sat, 26 May 2018 21:19:26 +0300 Subject: [PATCH] bpo-33652: Improve pickle support in the typing module. (GH-7123) Pickles of type variables and subscripted generics are now future-proof and compatible with older Python versions. --- Lib/typing.py | 27 +++++++++++++------ .../2018-05-26-10-13-59.bpo-33652.humFJ1.rst | 2 ++ 2 files changed, 21 insertions(+), 8 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2018-05-26-10-13-59.bpo-33652.humFJ1.rst diff --git a/Lib/typing.py b/Lib/typing.py index 18b04cf4db..e9265afce4 100644 --- a/Lib/typing.py +++ b/Lib/typing.py @@ -24,6 +24,7 @@ import collections import collections.abc import contextlib import functools +import operator import re as stdlib_re # Avoid confusion with the re we export. import sys import types @@ -486,10 +487,6 @@ class ForwardRef(_Final, _root=True): return f'ForwardRef({self.__forward_arg__!r})' -def _find_name(mod, name): - return getattr(sys.modules[mod], name) - - class TypeVar(_Final, _Immutable, _root=True): """Type variable. @@ -535,7 +532,7 @@ class TypeVar(_Final, _Immutable, _root=True): """ __slots__ = ('__name__', '__bound__', '__constraints__', - '__covariant__', '__contravariant__', '_def_mod') + '__covariant__', '__contravariant__') def __init__(self, name, *constraints, bound=None, covariant=False, contravariant=False): @@ -554,7 +551,9 @@ class TypeVar(_Final, _Immutable, _root=True): self.__bound__ = _type_check(bound, "Bound must be a type.") else: self.__bound__ = None - self._def_mod = sys._getframe(1).f_globals['__name__'] # for pickling + def_mod = sys._getframe(1).f_globals['__name__'] # for pickling + if def_mod != 'typing': + self.__module__ = def_mod def __getstate__(self): return {'name': self.__name__, @@ -580,7 +579,7 @@ class TypeVar(_Final, _Immutable, _root=True): return prefix + self.__name__ def __reduce__(self): - return (_find_name, (self._def_mod, self.__name__)) + return self.__name__ # Special typing constructs Union, Optional, Generic, Callable and Tuple @@ -741,7 +740,19 @@ class _GenericAlias(_Final, _root=True): def __reduce__(self): if self._special: return self._name - return super().__reduce__() + + if self._name: + origin = globals()[self._name] + else: + origin = self.__origin__ + if (origin is Callable and + not (len(self.__args__) == 2 and self.__args__[0] is Ellipsis)): + args = list(self.__args__[:-1]), self.__args__[-1] + else: + args = tuple(self.__args__) + if len(args) == 1 and not isinstance(args[0], tuple): + args, = args + return operator.getitem, (origin, args) class _VariadicGenericAlias(_GenericAlias, _root=True): diff --git a/Misc/NEWS.d/next/Library/2018-05-26-10-13-59.bpo-33652.humFJ1.rst b/Misc/NEWS.d/next/Library/2018-05-26-10-13-59.bpo-33652.humFJ1.rst new file mode 100644 index 0000000000..f5499f1b53 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2018-05-26-10-13-59.bpo-33652.humFJ1.rst @@ -0,0 +1,2 @@ +Pickles of type variables and subscripted generics are now future-proof and +compatible with older Python versions. -- 2.40.0