Add 3.13 compatibility (#129)

* Pull dataclasses remove functions into module

* explicitly pass no type params to _eval_type() to suppress warning

* Only add eval type param on 3.13 or greater

* Address comments

---------

Co-authored-by: Ritvik Nag <[email protected]>

dataclass_wizard/constants.py

@@ -26,6 +26,9 @@
 # Check if currently running Python 3.11 or higher
 PY311_OR_ABOVE = _PY_VERSION >= (3, 11)
 
+# Check if currently running Python 3.13 or higher
+PY313_OR_ABOVE = _PY_VERSION >= (3, 13)
+
 # The name of the dictionary object that contains `load` hooks for each
 # object type. Also used to check if a class is a :class:`BaseLoadHook`
 _LOAD_HOOKS = '__LOAD_HOOKS__'

dataclass_wizard/models.py

@@ -1,6 +1,5 @@
 import json
-# noinspection PyProtectedMember
-from dataclasses import MISSING, Field, _create_fn
+from dataclasses import MISSING, Field
 from datetime import date, datetime, time
 from typing import (cast, Collection, Callable,
                     Optional, List, Union, Type, Generic)
@@ -9,6 +8,8 @@
 from .constants import PY310_OR_ABOVE
 from .decorators import cached_property
 from .type_def import T, DT, Encoder, PyTypedDict, FileEncoder
+# noinspection PyProtectedMember
+from .utils.dataclass_compat import _create_fn
 from .utils.type_conv import as_datetime, as_time, as_date
 
 

dataclass_wizard/serial_json.py

@@ -1,6 +1,4 @@
 import json
-# noinspection PyProtectedMember
-from dataclasses import _create_fn, _set_new_attribute
 from typing import Type, List, Union, AnyStr
 
 from .abstractions import AbstractJSONWizard, W
@@ -10,6 +8,8 @@
 from .dumpers import asdict
 from .loaders import fromdict, fromlist
 from .type_def import Decoder, Encoder, JSONObject, ListOfJSONObject
+# noinspection PyProtectedMember
+from .utils.dataclass_compat import _create_fn, _set_new_attribute
 
 
 class JSONSerializable(AbstractJSONWizard):

dataclass_wizard/utils/dataclass_compat.py

@@ -0,0 +1,59 @@
+"""
+Pulling some functions removed in recent versions of Python into the module for continued compatibility.
+All function names and bodies are left exactly as they were prior to being removed.
+"""
+
+from dataclasses import MISSING
+from types import FunctionType
+
+
+def _set_qualname(cls, value):
+    # Removed in Python 3.13
+    # Original: `dataclasses._set_qualname`
+    # Ensure that the functions returned from _create_fn uses the proper
+    # __qualname__ (the class they belong to).
+    if isinstance(value, FunctionType):
+        value.__qualname__ = f"{cls.__qualname__}.{value.__name__}"
+    return value
+
+
+def _set_new_attribute(cls, name, value):
+    # Removed in Python 3.13
+    # Original: `dataclasses._set_new_attribute`
+    # Never overwrites an existing attribute.  Returns True if the
+    # attribute already exists.
+    if name in cls.__dict__:
+        return True
+    _set_qualname(cls, value)
+    setattr(cls, name, value)
+    return False
+
+
+def _create_fn(name, args, body, *, globals=None, locals=None,
+               return_type=MISSING):
+    # Removed in Python 3.13
+    # Original: `dataclasses._create_fn`
+    # Note that we may mutate locals. Callers beware!
+    # The only callers are internal to this module, so no
+    # worries about external callers.
+    if locals is None:
+        locals = {}
+    return_annotation = ''
+    if return_type is not MISSING:
+        locals['__dataclass_return_type__'] = return_type
+        return_annotation = '->__dataclass_return_type__'
+    args = ','.join(args)
+    body = '\n'.join(f'  {b}' for b in body)
+
+    # Compute the text of the entire function.
+    txt = f' def {name}({args}){return_annotation}:\n{body}'
+
+    # Free variables in exec are resolved in the global namespace.
+    # The global namespace we have is user-provided, so we can't modify it for
+    # our purposes. So we put the things we need into locals and introduce a
+    # scope to allow the function we're creating to close over them.
+    local_vars = ', '.join(locals.keys())
+    txt = f"def __create_fn__({local_vars}):\n{txt}\n return {name}"
+    ns = {}
+    exec(txt, globals, ns)
+    return ns['__create_fn__'](**locals)

dataclass_wizard/utils/typing_compat.py

@@ -22,7 +22,7 @@
 from collections.abc import Callable
 
 from .string_conv import repl_or_with_union
-from ..constants import PY36, PY38, PY310_OR_ABOVE, PY39
+from ..constants import PY36, PY38, PY310_OR_ABOVE, PY313_OR_ABOVE, PY39
 from ..type_def import FREF, PyLiteral, PyTypedDicts, PyForwardRef
 
 
@@ -85,11 +85,9 @@ def get_keys_for_typed_dict(cls):
     except ImportError:
         from typing import _AnnotatedAlias
 
-
     def _is_annotated(cls):
         return isinstance(cls, _AnnotatedAlias)
 
-
     def _is_base_generic(cls):
         if isinstance(cls, typing._GenericAlias):
             if cls.__origin__ in {typing.Generic, typing._Protocol}:
@@ -142,7 +140,6 @@ def is_literal(cls) -> bool:
         def _process_forward_annotation(base_type):
             return PyForwardRef(base_type, is_argument=False)
 
-
         def _get_origin(cls, raise_=False):
             if isinstance(cls, types.UnionType):
                 return typing.Union
@@ -180,7 +177,6 @@ def _get_origin(cls, raise_=False):
                     raise
                 return cls
 
-
     def _get_named_tuple_field_types(cls, raise_=True):
         """
         Note: The latest Python versions only support the `__annotations__`
@@ -204,12 +200,10 @@ def _get_named_tuple_field_types(cls, raise_=True):
 
     from typing_extensions import AnnotatedMeta
 
-
     def _process_forward_annotation(base_type):
         return PyForwardRef(
             repl_or_with_union(base_type), is_argument=False)
 
-
     def _is_base_generic(cls):
         if isinstance(cls, (typing.GenericMeta, typing._Union)):
             return cls.__args__ in {None, ()}
@@ -248,7 +242,6 @@ def _get_origin(cls, raise_=False):
                     raise
                 return cls
 
-
     def _get_args(cls):
         if is_literal(cls):
             return cls.__values__
@@ -266,7 +259,6 @@ def _get_args(cls):
             #   my_union: Union
             return ()
 
-
     def _get_named_tuple_field_types(cls, raise_=True):
         """
         Note: Prior to PEP 526, only `_field_types` attribute was assigned.
@@ -372,8 +364,12 @@ def eval_forward_ref(base_type: FREF,
     # Evaluate the ForwardRef here
     base_globals = sys.modules[cls.__module__].__dict__
 
-    # noinspection PyProtectedMember
-    return typing._eval_type(base_type, base_globals, _TYPING_LOCALS)
+    if PY313_OR_ABOVE:
+        # noinspection PyProtectedMember
+        return typing._eval_type(base_type, base_globals, _TYPING_LOCALS, type_params=())
+    else:
+        # noinspection PyProtectedMember
+        return typing._eval_type(base_type, base_globals, _TYPING_LOCALS)
 
 
 def eval_forward_ref_if_needed(base_type: typing.Union[typing.Type, FREF],