Same content as rev b5c043b

changelog.d/847.change.rst

@@ -0,0 +1,2 @@
+Attrs classes are now fully compatible with cloudpickle.
+`#847 <https://github.com/python-attrs/attrs/issues/847>`_

setup.py

@@ -47,7 +47,7 @@
 EXTRAS_REQUIRE = {
     "docs": ["furo", "sphinx", "zope.interface", "sphinx-notfound-page"],
     "tests_no_zope": [
-        # Regression test to ensure cloudpickle compat doesn't break.
+        # For regression test to ensure cloudpickle compat doesn't break.
         "cloudpickle",
         # 5.0 introduced toml; parallel was broken until 5.0.2
         "coverage[toml]>=5.0.2",

src/attr/_make.py

@@ -8,7 +8,21 @@
 
 from operator import itemgetter
 
+# We need to import _compat itself in addition to the _compat members to avoid
+# having the thread-local in the globals here.
 from . import _compat, _config, setters
+from ._compat import (
+    HAS_F_STRINGS,
+    PY2,
+    PY310,
+    PYPY,
+    isclass,
+    iteritems,
+    metadata_proxy,
+    new_class,
+    ordered_dict,
+    set_closure_cell,
+)
 from .exceptions import (
     DefaultAlreadySetError,
     FrozenInstanceError,
@@ -18,7 +32,7 @@
 )
 
 
-if not _compat.PY2:
+if not PY2:
     import typing
 
 
@@ -40,7 +54,7 @@
 # (when slots=True)
 _hash_cache_field = "_attrs_cached_hash"
 
-_empty_metadata_singleton = _compat.metadata_proxy({})
+_empty_metadata_singleton = metadata_proxy({})
 
 # Unique object for unequivocal getattr() defaults.
 _sentinel = object()
@@ -90,7 +104,7 @@ class _CacheHashWrapper(int):
     See GH #613 for more details.
     """
 
-    if _compat.PY2:
+    if PY2:
         # For some reason `type(None)` isn't callable in Python 2, but we don't
         # actually need a constructor for None objects, we just need any
         # available function that returns None.
@@ -508,9 +522,9 @@ def _transform_attrs(
     anns = _get_annotations(cls)
 
     if these is not None:
-        ca_list = [(name, ca) for name, ca in _compat.iteritems(these)]
+        ca_list = [(name, ca) for name, ca in iteritems(these)]
 
-        if not isinstance(these, _compat.ordered_dict):
+        if not isinstance(these, ordered_dict):
             ca_list.sort(key=_counter_getter)
     elif auto_attribs is True:
         ca_names = {
@@ -600,7 +614,7 @@ def _transform_attrs(
     return _Attributes((AttrsClass(attrs), base_attrs, base_attr_map))
 
 
-if _compat.PYPY:
+if PYPY:
 
     def _frozen_setattrs(self, name, value):
         """
@@ -782,7 +796,7 @@ def _create_slots_class(self):
         """
         cd = {
             k: v
-            for k, v in _compat.iteritems(self._cls_dict)
+            for k, v in iteritems(self._cls_dict)
             if k not in tuple(self._attr_names) + ("__dict__", "__weakref__")
         }
 
@@ -837,7 +851,7 @@ def _create_slots_class(self):
         # we collect them here and update the class dict
         reused_slots = {
             slot: slot_descriptor
-            for slot, slot_descriptor in _compat.iteritems(existing_slots)
+            for slot, slot_descriptor in iteritems(existing_slots)
             if slot in slot_names
         }
         slot_names = [name for name in slot_names if name not in reused_slots]
@@ -880,7 +894,7 @@ def _create_slots_class(self):
                     pass
                 else:
                     if match:
-                        _compat.set_closure_cell(cell, cls)
+                        set_closure_cell(cell, cls)
 
         return cls
 
@@ -1462,7 +1476,7 @@ def attrs(
     .. versionchanged:: 21.1.0 *cmp* undeprecated
     .. versionadded:: 21.3.0 *match_args*
     """
-    if auto_detect and _compat.PY2:
+    if auto_detect and PY2:
         raise PythonTooOldError(
             "auto_detect only works on Python 3 and later."
         )
@@ -1578,7 +1592,7 @@ def wrap(cls):
                 )
 
         if (
-            _compat.PY310
+            PY310
             and match_args
             and not _has_own_attribute(cls, "__match_args__")
         ):
@@ -1601,7 +1615,7 @@ def wrap(cls):
 """
 
 
-if _compat.PY2:
+if PY2:
 
     def _has_frozen_base_class(cls):
         """
@@ -1653,7 +1667,7 @@ def _make_hash(cls, attrs, frozen, cache_hash):
     if not cache_hash:
         hash_def += "):"
     else:
-        if not _compat.PY2:
+        if not PY2:
             hash_def += ", *"
 
         hash_def += (
@@ -1851,7 +1865,7 @@ def _add_eq(cls, attrs=None):
     return cls
 
 
-if _compat.HAS_F_STRINGS:
+if HAS_F_STRINGS:
 
     def _make_repr(attrs, ns, cls):
         unique_filename = "repr"
@@ -1893,24 +1907,23 @@ def _make_repr(attrs, ns, cls):
         else:
             cls_name_fragment = ns + ".{self.__class__.__name__}"
 
-        lines = []
-        lines.append("def __repr__(self):")
-        lines.append("  try:")
-        lines.append("    working_set = _compat.repr_context.working_set")
-        lines.append("  except AttributeError:")
-        lines.append("    working_set = {id(self),}")
-        lines.append("    _compat.repr_context.working_set = working_set")
-        lines.append("  else:")
-        lines.append("    if id(self) in working_set:")
-        lines.append("      return '...'")
-        lines.append("    else:")
-        lines.append("      working_set.add(id(self))")
-        lines.append("  try:")
-        lines.append(
-            "    return f'%s(%s)'" % (cls_name_fragment, repr_fragment)
-        )
-        lines.append("  finally:")
-        lines.append("    working_set.remove(id(self))")
+        lines = [
+            "def __repr__(self):",
+            "  try:",
+            "    already_repring = _compat.repr_context.already_repring",
+            "  except AttributeError:",
+            "    already_repring = {id(self),}",
+            "    _compat.repr_context.already_repring = already_repring",
+            "  else:",
+            "    if id(self) in already_repring:",
+            "      return '...'",
+            "    else:",
+            "      already_repring.add(id(self))",
+            "  try:",
+            "    return f'%s(%s)'" % (cls_name_fragment, repr_fragment),
+            "  finally:",
+            "    already_repring.remove(id(self))",
+        ]
 
         return _make_method(
             "__repr__", "\n".join(lines), unique_filename, globs=globs
@@ -1939,12 +1952,12 @@ def __repr__(self):
             Automatically created by attrs.
             """
             try:
-                working_set = _compat.repr_context.working_set
+                already_repring = _compat.repr_context.already_repring
             except AttributeError:
-                working_set = set()
-                _compat.repr_context.working_set = working_set
+                already_repring = set()
+                _compat.repr_context.already_repring = already_repring
 
-            if id(self) in working_set:
+            if id(self) in already_repring:
                 return "..."
             real_cls = self.__class__
             if ns is None:
@@ -1964,7 +1977,7 @@ def __repr__(self):
             # for the duration of this call, it's safe to depend on id(...)
             # stability, and not need to track the instance and therefore
             # worry about properties like weakref- or hash-ability.
-            working_set.add(id(self))
+            already_repring.add(id(self))
             try:
                 result = [class_name, "("]
                 first = True
@@ -1978,7 +1991,7 @@ def __repr__(self):
                     )
                 return "".join(result) + ")"
             finally:
-                working_set.remove(id(self))
+                already_repring.remove(id(self))
 
         return __repr__
 
@@ -2012,7 +2025,7 @@ def fields(cls):
     ..  versionchanged:: 16.2.0 Returned tuple allows accessing the fields
         by name.
     """
-    if not _compat.isclass(cls):
+    if not isclass(cls):
         raise TypeError("Passed object must be a class.")
     attrs = getattr(cls, "__attrs_attrs__", None)
     if attrs is None:
@@ -2040,14 +2053,14 @@ def fields_dict(cls):
 
     .. versionadded:: 18.1.0
     """
-    if not _compat.isclass(cls):
+    if not isclass(cls):
         raise TypeError("Passed object must be a class.")
     attrs = getattr(cls, "__attrs_attrs__", None)
     if attrs is None:
         raise NotAnAttrsClassError(
             "{cls!r} is not an attrs-decorated class.".format(cls=cls)
         )
-    return _compat.ordered_dict(((a.name, a) for a in attrs))
+    return ordered_dict(((a.name, a) for a in attrs))
 
 
 def validate(inst):
@@ -2200,7 +2213,7 @@ def _assign_with_converter(attr_name, value_var, has_on_setattr):
     )
 
 
-if _compat.PY2:
+if PY2:
 
     def _unpack_kw_only_py2(attr_name, default=None):
         """
@@ -2474,7 +2487,7 @@ def fmt_setter_with_converter(
         if a.init is True:
             if a.type is not None and a.converter is None:
                 annotations[arg_name] = a.type
-            elif a.converter is not None and not _compat.PY2:
+            elif a.converter is not None and not PY2:
                 # Try to get the type from the converter.
                 sig = None
                 try:
@@ -2531,7 +2544,7 @@ def fmt_setter_with_converter(
 
     args = ", ".join(args)
     if kw_only_args:
-        if _compat.PY2:
+        if PY2:
             lines = _unpack_kw_only_lines_py2(kw_only_args) + lines
 
             args += "%s**_kw_only" % (", " if args else "",)  # leading comma
@@ -2650,7 +2663,7 @@ def __init__(
         bound_setattr(
             "metadata",
             (
-                _compat.metadata_proxy(metadata)
+                metadata_proxy(metadata)
                 if metadata
                 else _empty_metadata_singleton
             ),
@@ -2745,7 +2758,7 @@ def _setattrs(self, name_values_pairs):
             else:
                 bound_setattr(
                     name,
-                    _compat.metadata_proxy(value)
+                    metadata_proxy(value)
                     if value
                     else _empty_metadata_singleton,
                 )
@@ -3021,7 +3034,7 @@ def make_class(name, attrs, bases=(object,), **attributes_arguments):
     if user_init is not None:
         body["__init__"] = user_init
 
-    type_ = _compat.new_class(name, bases, {}, lambda ns: ns.update(body))
+    type_ = new_class(name, bases, {}, lambda ns: ns.update(body))
 
     # For pickling to work, the __module__ variable needs to be set to the
     # frame where the class is created.  Bypass this step in environments where
@@ -3108,7 +3121,7 @@ def pipe_converter(val):
 
         return val
 
-    if not _compat.PY2:
+    if not PY2:
         if not converters:
             # If the converter list is empty, pipe_converter is the identity.
             A = typing.TypeVar("A")

tests/test_compatibility.py

@@ -16,6 +16,9 @@ class TestCloudpickleCompat(object):
 
     @given(simple_classes())
     def test_repr(self, cls):
+        """
+        attrs instances can be pickled and un-pickled with cloudpickle.
+        """
         inst = cls()
         # Exact values aren't a concern so long as neither direction
         # raises an exception.