Rename _single_instances to _singular_instances in Singular class and update related references

Author: fleming79

ipylab/common.py

@@ -609,8 +609,8 @@ class Singular(HasTraits):
     """A base class that ensures only one instance of a class exists for each unique
     key (except for None).
 
-    This class uses a class-level dictionary `_single_instances` to store instances,
-    keyed by a value obtained from the `get_single_key` method.  Subsequent calls to
+    This class uses a class-level dictionary `_singular_instances` to store instances,
+    keyed by a value obtained from the `get_single_key` classmethod.  Subsequent calls to
     the constructor with the same key will return the existing instance. If key is
     None, a new instance is always created and a reference is not kept to the object.
 
@@ -619,13 +619,13 @@ class Singular(HasTraits):
     """
 
     singular_init_started = traitlets.Bool(read_only=True)
-    _single_instances: ClassVar[dict[Hashable, Self]] = {}
+    _singular_instances: ClassVar[dict[Hashable, Self]] = {}
     single_key = AnyTrait(default_value=None, allow_none=True, read_only=True)
     closed = Bool(read_only=True)
     singular: ClassVar[_SingularInstances[Self]]
 
     def __init_subclass__(cls) -> None:
-        cls._single_instances = {}
+        cls._singular_instances = {}
         cls.singular = _SingularInstances()
 
     @classmethod
@@ -634,11 +634,11 @@ def get_single_key(cls, *args, **kwgs) -> Hashable:  # noqa: ARG003
 
     def __new__(cls, /, *args, **kwgs) -> Self:
         key = cls.get_single_key(*args, **kwgs)
-        if key is None or not (inst := cls._single_instances.get(key)):
+        if key is None or not (inst := cls._singular_instances.get(key)):
             new = super().__new__
             inst = new(cls) if new is object.__new__ else new(cls, *args, **kwgs)
             if key:
-                cls._single_instances[key] = inst
+                cls._singular_instances[key] = inst
                 inst.set_trait("single_key", key)
         return inst
 
@@ -647,13 +647,13 @@ def __init__(self, /, *args, **kwgs):
             return
         self.set_trait("singular_init_started", True)
         super().__init__(*args, **kwgs)
-        self.singular.set_trait("instances", tuple(self._single_instances.values()))
+        self.singular.set_trait("instances", tuple(self._singular_instances.values()))
 
     @observe("closed")
     def _singular_observe_closed(self, _):
         if self.closed and self.single_key is not None:
-            self._single_instances.pop(self.single_key, None)
-            self.singular.set_trait("instances", tuple(self._single_instances.values()))
+            self._singular_instances.pop(self.single_key, None)
+            self.singular.set_trait("instances", tuple(self._singular_instances.values()))
 
     def close(self):
         if close := getattr(super(), "close", None):

ipylab/connection.py

@@ -60,11 +60,11 @@ def get_single_key(cls, cid: str, **kwgs) -> Hashable:
 
     @classmethod
     def exists(cls, cid: str) -> bool:
-        return cid in cls._single_instances
+        return cid in cls._singular_instances
 
     @classmethod
     def close_if_exists(cls, cid: str):
-        if inst := cls._single_instances.pop(cid, None):
+        if inst := cls._singular_instances.pop(cid, None):
             inst.close()
 
     def __init_subclass__(cls, **kwargs) -> None:

tests/test_common.py

@@ -181,7 +181,7 @@ class MySingular(Singular):
         obj2 = MySingular()
         assert obj1 is obj2
         obj1.close()
-        assert obj1 not in obj1._single_instances
+        assert obj1 not in obj1._singular_instances
         assert obj1.closed
 
     async def test_limited_newget_single_keyed(self):
@@ -204,12 +204,12 @@ def get_single_key(cls, key: str, **kwgs):
         obj5 = KeyedSingle(None)
         obj6 = KeyedSingle(None)
 
-        assert obj1 in KeyedSingle._single_instances.values()
+        assert obj1 in KeyedSingle._singular_instances.values()
         assert obj1 is obj2
         assert obj1 is not obj3
         assert obj4 is obj3
         assert obj5 is not obj6
-        assert obj5 not in KeyedSingle._single_instances.values()
+        assert obj5 not in KeyedSingle._singular_instances.values()
 
 
 class TestFixed: