Adapt new attributes api to mwdblib (#59)

mwdblib/object.py

@@ -161,6 +161,20 @@ def shares(self) -> List["MWDBShare"]:
             )
         return [MWDBShare(self.api, share, self) for share in self.data["shares"]]
 
+    @property
+    def attributes(self) -> Dict[str, List[Any]]:
+        """
+        Returns dict object with attributes.
+
+        :return: Dict object containing attributes
+        """
+        if "attributes" not in self.data:
+            self._load("object/{id}/attribute")
+        result = defaultdict(list)
+        for m in self.data["attributes"]:
+            result[m["key"]].append(m["value"])
+        return dict(result)
+
     @property
     def metakeys(self) -> Dict[str, List[str]]:
         """
@@ -285,6 +299,21 @@ def add_comment(self, comment: str) -> None:
         )
         self._expire("comments")
 
+    def add_attribute(self, key: str, value: Any) -> None:
+        """
+        Adds attribute
+
+        :param key: Attribute key
+        :type key: str
+        :param value: Attribute value
+        :type value: Any (JSON-like object)
+        """
+        self.api.post(
+            "object/{id}/attribute".format(**self.data),
+            json={"key": key, "value": value},
+        )
+        self._expire("attributes")
+
     def add_metakey(self, key: str, value: str) -> None:
         """
         Adds metakey attribute