diff options
| -rw-r--r-- | Lib/typing.py | 14 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Library/2023-12-04-14-05-24.gh-issue-74690.eODKRm.rst | 5 |
2 files changed, 16 insertions, 3 deletions
diff --git a/Lib/typing.py b/Lib/typing.py index 4c19aad..aa64ed9 100644 --- a/Lib/typing.py +++ b/Lib/typing.py @@ -1782,6 +1782,14 @@ copyreg.pickle(ParamSpecKwargs, _pickle_pskwargs) del _pickle_psargs, _pickle_pskwargs +# Preload these once, as globals, as a micro-optimisation. +# This makes a significant difference to the time it takes +# to do `isinstance()`/`issubclass()` checks +# against runtime-checkable protocols with only one callable member. +_abc_instancecheck = ABCMeta.__instancecheck__ +_abc_subclasscheck = ABCMeta.__subclasscheck__ + + class _ProtocolMeta(ABCMeta): # This metaclass is somewhat unfortunate, # but is necessary for several reasons... @@ -1841,7 +1849,7 @@ class _ProtocolMeta(ABCMeta): "Instance and class checks can only be used with " "@runtime_checkable protocols" ) - return super().__subclasscheck__(other) + return _abc_subclasscheck(cls, other) def __instancecheck__(cls, instance): # We need this method for situations where attributes are @@ -1850,7 +1858,7 @@ class _ProtocolMeta(ABCMeta): return type.__instancecheck__(cls, instance) if not getattr(cls, "_is_protocol", False): # i.e., it's a concrete subclass of a protocol - return super().__instancecheck__(instance) + return _abc_instancecheck(cls, instance) if ( not getattr(cls, '_is_runtime_protocol', False) and @@ -1859,7 +1867,7 @@ class _ProtocolMeta(ABCMeta): raise TypeError("Instance and class checks can only be used with" " @runtime_checkable protocols") - if super().__instancecheck__(instance): + if _abc_instancecheck(cls, instance): return True getattr_static = _lazy_load_getattr_static() diff --git a/Misc/NEWS.d/next/Library/2023-12-04-14-05-24.gh-issue-74690.eODKRm.rst b/Misc/NEWS.d/next/Library/2023-12-04-14-05-24.gh-issue-74690.eODKRm.rst new file mode 100644 index 0000000..36d793f --- /dev/null +++ b/Misc/NEWS.d/next/Library/2023-12-04-14-05-24.gh-issue-74690.eODKRm.rst @@ -0,0 +1,5 @@ +Speedup :func:`isinstance` checks by roughly 20% for +:func:`runtime-checkable protocols <typing.runtime_checkable>` +that only have one callable member. +Speedup :func:`issubclass` checks for these protocols by roughly 10%. +Patch by Alex Waygood. |