compat python 3.7

src/psygnal/_dataclass_utils.py

@@ -4,7 +4,7 @@
 import dataclasses
 import sys
 import types
-from dataclasses import KW_ONLY, dataclass, fields
+from dataclasses import dataclass, fields
 from typing import (
     TYPE_CHECKING,
     Any,
@@ -19,6 +19,7 @@
 from typing_extensions import Protocol
 
 if TYPE_CHECKING:
+    from dataclasses import Field
     import attrs
     import msgspec
     from pydantic import BaseModel
@@ -46,6 +47,9 @@ class AttrsType:
     __attrs_attrs__: tuple[attrs.Attribute, ...]
 
 
+KW_ONLY = object()
+with contextlib.suppress(ImportError):
+    from dataclasses import KW_ONLY  # type: ignore
 _DATACLASS_PARAMS = "__dataclass_params__"
 with contextlib.suppress(ImportError):
     from dataclasses import _DATACLASS_PARAMS  # type: ignore
@@ -235,15 +239,23 @@ def iter_fields(
 class FieldOptions:
     name: str
     type_: type | None = None
-    _: KW_ONLY
+    _: KW_ONLY = KW_ONLY  # set the value for compatibility with python < 3.10
     alias: str | None = None
     skip: bool | None = None
     eq: EqOperator | None = None
     disable_setattr: bool | None = None
 
 
+def is_kw_only(f: Field):
+    if hasattr(f, "kw_only"):
+        return f.kw_only
+    # for python < 3.10
+    if f.name not in ["name", "type_"]:
+        return True
+    return False
+
 def sanitize_field_options_dict(d: Mapping) -> dict[str, Any]:
-    field_options_kws = [f.name for f in fields(FieldOptions) if f.kw_only]
+    field_options_kws = [f.name for f in fields(FieldOptions) if is_kw_only(f)]
     return {k: v for k, v in d.items() if k in field_options_kws}
 
 

src/psygnal/_evented_decorator.py

@@ -4,12 +4,8 @@
     TYPE_CHECKING,
     Any,
     Callable,
-    Dict,
     Mapping,
-    Optional,
-    Type,
     TypeVar,
-    Union,
     overload,
 )
 
@@ -20,7 +16,7 @@
 
 __all__ = ["evented"]
 
-T = TypeVar("T", bound=Type)
+T = TypeVar("T", bound=type)
 
 EqOperator = Callable[[Any, Any], bool]
 PSYGNAL_GROUP_NAME = "_psygnal_group_"
@@ -32,7 +28,7 @@ def evented(
     cls: T,
     *,
     events_namespace: str = "events",
-    equality_operators: Optional[Dict[str, EqOperator]] = None,
+    equality_operators: dict[str, EqOperator] | None = None,
     warn_on_no_fields: bool = ...,
     cache_on_instance: bool = ...,
     skip_private_fields: bool = ...,
@@ -44,10 +40,10 @@ def evented(
 
 @overload
 def evented(
-    cls: "Optional[Literal[None]]" = None,
+    cls: Literal[None] | None = None,
     *,
     events_namespace: str = "events",
-    equality_operators: Optional[Dict[str, EqOperator]] = None,
+    equality_operators: dict[str, EqOperator] | None = None,
     warn_on_no_fields: bool = ...,
     cache_on_instance: bool = ...,
     skip_private_fields: bool = ...,
@@ -58,16 +54,16 @@ def evented(
 
 
 def evented(
-    cls: Optional[T] = None,
+    cls: T | None = None,
     *,
     events_namespace: str = "events",
-    equality_operators: Optional[Dict[str, EqOperator]] = None,
+    equality_operators: dict[str, EqOperator] | None = None,
     warn_on_no_fields: bool = True,
     cache_on_instance: bool = True,
     skip_private_fields: bool = False,
     signal_suffix: str = "",
     signal_aliases: Mapping[str, str | None] | None = None,
-) -> Union[Callable[[T], T], T]:
+) -> Callable[[T], T] | T:
     """A decorator to add events to a dataclass.
 
     See also the documentation for
@@ -88,7 +84,7 @@ def evented(
         The class to decorate.
     events_namespace : str
         The name of the namespace to add the events to, by default `"events"`
-    equality_operators : Optional[Dict[str, Callable]]
+    equality_operators : dict[str, Callable] | None
         A dictionary mapping field names to equality operators (a function that takes
         two values and returns `True` if they are equal). These will be used to
         determine if a field has changed when setting a new value.  By default, this

src/psygnal/_group_descriptor.py

@@ -218,7 +218,8 @@ def _build_dataclass_signal_group(
             key = next((k for k, v in signal_aliases.items() if v == sig_name), None)
             warnings.warn(
                 f"Signal {sig_name} was already created in {group_name}, "
-                f"from field {key}"
+                f"from field {key}",
+                stacklevel=2,
             )
             continue
 

tests/test_custom_fields.py

@@ -1,4 +1,7 @@
-from typing import Annotated, ClassVar
+# from __future__ import annotations
+
+import contextlib
+from typing import TYPE_CHECKING, ClassVar, Union
 from unittest.mock import Mock
 
 import pytest
@@ -11,6 +14,12 @@
     SignalGroupDescriptor,
 )
 
+# from typing import Annotated  # type: ignore
+Annotated = Union
+with contextlib.suppress(ImportError):
+    from typing import Annotated  # type: ignore
+
+
 dataclass_types = ["dataclass", "pydantic", "pydantic_v1", "attrs", "msgspec"]