Feature/custom properties

CHANGELOG.rst

@@ -20,4 +20,4 @@ Changelog
 -----
 
 * Improved code quality
-
+* Add Entity.custom_properties

src/oemof/network/network/entity.py

@@ -42,6 +42,10 @@ class Entity:
         representation of this node will instead be generated based on this
         nodes `class` and `id`.
 
+    custom_properties: `dict`
+        This dictionary that can be used to store information that can be used
+        to easily attach custom information to any Entity.
+
     Attributes
     ----------
     __slots__: str or iterable of str
@@ -50,27 +54,21 @@ class Entity:
         information.
     """
 
-    __slots__ = ["_label", "_in_edges", "_inputs", "_outputs"]
+    __slots__ = [
+        "_label",
+        "_in_edges",
+        "_inputs",
+        "_outputs",
+        "custom_properties",
+    ]
 
-    def __init__(self, *args, **kwargs):
-        args = list(args)
+    def __init__(self, label=None, *, custom_properties=None, **kwargs):
+        self._label = label
+        if custom_properties is None:
+            custom_properties = {}
+        self.custom_properties = custom_properties
         self._inputs = Inputs(self)
         self._outputs = Outputs(self)
-        for optional in ["label"]:
-            if optional in kwargs:
-                if args:
-                    raise (
-                        TypeError(
-                            (
-                                "{}.__init__()\n"
-                                "  got multiple values for argument '{}'"
-                            ).format(type(self), optional)
-                        )
-                    )
-                setattr(self, "_" + optional, kwargs[optional])
-            else:
-                if args:
-                    setattr(self, "_" + optional, args.pop())
 
     def __eq__(self, other):
         return id(self) == id(other)
@@ -100,7 +98,7 @@ def label(self):
         """
         return (
             self._label
-            if hasattr(self, "_label")
+            if self._label is not None
             else "<{} #0x{:x}>".format(type(self).__name__, id(self))
         )
 

tests/test_network_classes.py

@@ -253,11 +253,10 @@ def test_entity_input_output_type_assertions(self):
 
     def test_node_label_without_private_attribute(self):
         """
-        A `Node` with no explicit `label` doesn't have a `_label` attribute.
+        A `Node` without `label` doesn't have the `_label` attribute set.
         """
         n = Node()
-        with pytest.raises(AttributeError):
-            n._label
+        assert not n._label
 
     def test_node_label_if_its_not_explicitly_specified(self):
         """If not explicitly given, a `Node`'s label is based on its `id`."""
@@ -351,3 +350,27 @@ def test_deprecated_classes():
         Source()
     with pytest.warns(FutureWarning):
         Transformer()
+
+
+def test_custom_properties():
+    node0 = Node()
+
+    assert not node0.custom_properties
+
+    node1 = Node(
+        custom_properties={
+            "foo": "bar",
+            1: 2,
+        }
+    )
+    assert node1.custom_properties["foo"] == "bar"
+    assert node1.custom_properties[1] == 2
+
+
+def test_comparision():
+    node0 = Node(label=0)
+    node1 = Node(label=2)
+    node2 = Node(label=-5)
+
+    assert node0 < node1
+    assert node0 > node2