Cleanup and de-nesting.

order/adapters/base.py

@@ -28,11 +28,7 @@ class AdapterModel(BaseModel):
 
     adapter: NonEmptyStrictStr
     key: StrictStr
-    arguments: Dict[NonEmptyStrictStr, Any] = Field(default_factory=lambda: {})
-
-    @property
-    def name(self) -> str:
-        return self.adapter
+    arguments: Dict[NonEmptyStrictStr, Any] = Field(default_factory=dict)
 
     def compare_signature(self, other: "AdapterModel") -> bool:
         return (
@@ -109,7 +105,6 @@ def retrieve_data(self) -> Materialized:
         return
 
     def get_cache_key(self, **kwargs) -> tuple:
-        # must be implemented by subclasses
         return tuple(
             (
                 key,
@@ -137,7 +132,7 @@ def remove_scheme(cls, data_location: str) -> str:
 
 class DataProvider(object):
     """
-    Interface between data locations plus caches and :py:class:`Adapter`'s.
+    Interface between data locations plus caches and :py:class:`Adapter` instances.
     """
 
     __instance = None
@@ -166,6 +161,7 @@ def instance(cls) -> "DataProvider":
 
     def __init__(
         self,
+        *,
         data_location: str,
         cache_directory: str,
         readonly_cache_directories: Sequence[str] = (),
@@ -202,7 +198,7 @@ def materialize(
             adapter_model = AdapterModel(**adapter_model)
 
         # get the adapter class and instantiate it
-        adapter = AdapterMeta.get_cls(adapter_model.name)()
+        adapter = AdapterMeta.get_cls(adapter_model.adapter)()
 
         # merge kwargs
         adapter_kwargs = {**adapter_model.arguments, **(adapter_kwargs or {})}
@@ -231,7 +227,7 @@ def materialize(
         # complain when the return value is not a materialized container
         if not isinstance(materialized, Materialized):
             raise TypeError(
-                f"retrieve_data of adapter '{adapter_model.name}' must return Materialized "
+                f"retrieve_data of adapter '{adapter_model.adapter}' must return a Materialized "
                 f"instance, but got '{materialized}'",
             )
 

order/models/base.py

@@ -122,7 +122,7 @@ def fget(self):
                     # complain when the adapter did not provide a value for this attribute
                     if adapter_model_.key not in materialized:
                         raise KeyError(
-                            f"adapter '{adapter_model.name}' did not provide field "
+                            f"adapter '{adapter_model.adapter}' did not provide field "
                             f"'{adapter_model_.key}' as required by attribute '{attr_}'",
                         )
 
@@ -173,4 +173,4 @@ def __repr_args__(self) -> GeneratorType:
                 continue
 
             value = getattr(self, lazy_attr)
-            yield attr, f"lazy({value.name})" if isinstance(value, AdapterModel) else value
+            yield attr, f"lazy({value.adapter})" if isinstance(value, AdapterModel) else value

order/models/dataset.py

@@ -96,7 +96,4 @@ class LazyDataset(LazyUniqueObject):
 class DatasetIndex(UniqueObjectIndex):
 
     class_name: NonEmptyStrictStr = Field(default=Dataset)
-    objects: Lazy[List[Union[Dataset, LazyDataset]]] = Field(
-        default_factory=lambda: [],
-        repr=False,
-    )
+    objects: Lazy[List[Union[Dataset, LazyDataset]]] = Field(default_factory=list, repr=False)

order/models/unique.py

@@ -280,7 +280,7 @@ class UniqueObjectIndex(WrapsUniqueClcass):
     """
 
     objects: Lazy[List[Union[UniqueObject, LazyUniqueObject]]] = Field(
-        default_factory=lambda: [],
+        default_factory=list,
         repr=False,
     )
 
@@ -338,7 +338,7 @@ def __iter__(self) -> GeneratorType:
         for obj in self.objects:
             yield self.get(obj.name)
 
-    def __nonzero__(self):
+    def __nonzero__(self) -> bool:
         """
         Boolish conversion that depends on the number of objects in the index.
         """
@@ -470,7 +470,7 @@ def get(self, obj: Any, default: T = no_value) -> UniqueObject | T:
                 # remember the position of the object
                 idx = self.objects.index(_obj)
 
-                # materializee
+                # materialize
                 with _obj.materialize(self) as _obj:
                     # add back the materialized object
                     self.objects[idx] = _obj
@@ -489,20 +489,26 @@ def get_first(self, default: T = no_value) -> UniqueObject | T:
         Returns the first object of this index. If no object could be found, *default* is returned
         if set. An exception is raised otherwise.
         """
-        if not self.objects and default != no_value:
+        if self.objects:
+            return self.get(self.objects[0].name)
+
+        if default != no_value:
             return default
 
-        return self.get(self.objects[0].name)
+        raise Exception(f"cannot return first object, '{self}' is empty")
 
     def get_last(self, default: T = no_value) -> UniqueObject | T:
         """
         Returns the last object of this index. If no object could be found, *default* is returned if
         set. An exception is raised otherwise.
         """
-        if not self.objects and default != no_value:
+        if self.objects:
+            return self.get(self.objects[-1].name)
+
+        if default != no_value:
             return default
 
-        return self.get(self.objects[-1].name)
+        raise Exception(f"cannot return last object, '{self}' is empty")
 
     def add(
         self,

order/util.py

@@ -70,7 +70,7 @@ def __init__(
         self._getter = getter
         self._setter = setter
 
-    def __call__(self, *args, **kwargs):
+    def __call__(self, *args, **kwargs) -> Any:
         return self._getter(*args, **kwargs)
 
     def __getattr__(self, attr: str) -> Any: