diff --git a/Lib/copy.py b/Lib/copy.py index f27e109973cfb7..c64fc0761793f5 100644 --- a/Lib/copy.py +++ b/Lib/copy.py @@ -67,13 +67,15 @@ def copy(x): cls = type(x) - copier = _copy_dispatch.get(cls) - if copier: - return copier(x) + if cls in _copy_atomic_types: + return x + if cls in _copy_builtin_containers: + return cls.copy(x) + if issubclass(cls, type): # treat it as a regular class: - return _copy_immutable(x) + return x copier = getattr(cls, "__copy__", None) if copier is not None: @@ -98,23 +100,12 @@ def copy(x): return _reconstruct(x, None, *rv) -_copy_dispatch = d = {} - -def _copy_immutable(x): - return x -for t in (types.NoneType, int, float, bool, complex, str, tuple, +_copy_atomic_types = {types.NoneType, int, float, bool, complex, str, tuple, bytes, frozenset, type, range, slice, property, types.BuiltinFunctionType, types.EllipsisType, types.NotImplementedType, types.FunctionType, types.CodeType, - weakref.ref, super): - d[t] = _copy_immutable - -d[list] = list.copy -d[dict] = dict.copy -d[set] = set.copy -d[bytearray] = bytearray.copy - -del d, t + weakref.ref, super} +_copy_builtin_containers = {list, dict, set, bytearray} def deepcopy(x, memo=None, _nil=[]): """Deep copy operation on arbitrary Python objects. diff --git a/Misc/NEWS.d/next/Library/2024-12-20-10-57-10.gh-issue-128118.mYak8i.rst b/Misc/NEWS.d/next/Library/2024-12-20-10-57-10.gh-issue-128118.mYak8i.rst new file mode 100644 index 00000000000000..bc2898edfda721 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2024-12-20-10-57-10.gh-issue-128118.mYak8i.rst @@ -0,0 +1,2 @@ +Improve performance of :func:`copy.copy` by 30% via +a fast path for atomic types and container types.