Merge pull request #267 from juliamcclellan/attribute_builder

Attribute spec

CHANGELOG.md

@@ -5,6 +5,7 @@
   - [#67](https://github.com/Datatamer/unify-client-python/issues/67) Create a dataset from a pandas `DataFrame`
   - [#222](https://github.com/Datatamer/unify-client-python/issues/222) Dataset spec to update an existing dataset
   - [#225](https://github.com/Datatamer/unify-client-python/issues/225) Attribute configuration spec to update an existing attribute configuration
+  - [#223](https://github.com/Datatamer/unify-client-python/issues/223) Update an attribute with an attribute spec
 
   **BUG FIXES**
   - [#235](https://github.com/Datatamer/unify-client-python/issues/235) Making `AttributeCollection` retrieve attributes directly instead of by streaming

docs/developer-interface.rst

@@ -22,6 +22,12 @@ Attribute
 .. autoclass:: tamr_unify_client.attribute.resource.Attribute
   :members:
 
+Attribute Spec
+^^^^^^^^^^^^^^
+
+.. autoclass:: tamr_unify_client.attribute.resource.AttributeSpec
+  :members:
+
 Attribute Collection
 ^^^^^^^^^^^^^^^^^^^^
 

tamr_unify_client/attribute/resource.py

@@ -1,3 +1,5 @@
+from copy import deepcopy
+
 from tamr_unify_client.attribute.type import AttributeType
 from tamr_unify_client.base_resource import BaseResource
 
@@ -52,10 +54,88 @@ def is_nullable(self):
         """:type: bool"""
         return self._data.get("isNullable")
 
+    def spec(self):
+        """Returns a spec representation of this attribute.
+
+        :return: The attribute spec.
+        :rtype: :class:`~tamr_unify_client.attribute.resource.AttributeSpec`
+        """
+        return AttributeSpec.of(self)
+
     def __repr__(self):
         return (
             f"{self.__class__.__module__}."
             f"{self.__class__.__qualname__}("
             f"relative_id={self.relative_id!r}, "
             f"name={self.name!r})"
         )
+
+
+class AttributeSpec:
+    """A representation of the server view of an attribute"""
+
+    def __init__(self, client, data, api_path):
+        self._data = data
+        self.client = client
+        self.api_path = api_path
+
+    @staticmethod
+    def of(resource):
+        """Creates an attribute spec from an attribute.
+
+        :param resource: The existing attribute.
+        :type resource: :class:`~tamr_unify_client.attribute.resource.Attribute`
+        :return: The corresponding attribute spec.
+        :rtype: :class:`~tamr_unify_client.attribute.resource.AttributeSpec`
+        """
+        return AttributeSpec(
+            resource.client, deepcopy(resource._data), resource.api_path
+        )
+
+    def from_data(self, data):
+        """Creates a spec with the same client and API path as this one, but new data.
+
+        :param data: The data for the new spec.
+        :type data: dict
+        :return: The new spec.
+        :rtype: :class:`~tamr_unify_client.attribute.resource.AttributeSpec`
+        """
+        return AttributeSpec(self.client, data, self.api_path)
+
+    def to_dict(self):
+        """Returns a version of this spec that conforms to the API representation.
+
+        :returns: The spec's dict.
+        :rtype: dict
+        """
+        return deepcopy(self._data)
+
+    def with_description(self, new_description):
+        """Creates a new spec with the same properties, updating description.
+
+        :param new_description: The new description.
+        :type new_description: str
+        :return: The new spec.
+        :rtype: :class:`~tamr_unify_client.attribute.resource.AttributeSpec`
+        """
+        return self.from_data({**self._data, "description": new_description})
+
+    def put(self):
+        """Commits the changes and updates the attribute in Tamr.
+
+        :return: The updated attribute.
+        :rtype: :class:`~tamr_unify_client.attribute.resource.Attribute`
+        """
+        updated_attribute = (
+            self.client.put(self.api_path, json=self._data).successful().json()
+        )
+        return Attribute.from_json(self.client, updated_attribute, self.api_path)
+
+    def __repr__(self):
+        return (
+            f"{self.__class__.__module__}."
+            f"{self.__class__.__qualname__}("
+            f"relative_id={self.api_path!r}, "
+            f"name={self._data['name']!r}, "
+            f"description={self._data['description']!r})"
+        )

tests/unit/test_attribute.py

@@ -1,3 +1,5 @@
+from functools import partial
+import json
 from unittest import TestCase
 
 from requests import HTTPError
@@ -91,6 +93,41 @@ def test_delete_attribute(self):
             HTTPError, lambda: dataset.attributes.by_resource_id("RowNum")
         )
 
+    @responses.activate
+    def test_update_attribute(self):
+        def create_callback(request, snoop):
+            snoop["payload"] = request.body
+            return 200, {}, json.dumps(self._updated_attribute_json)
+
+        relative_id = "dataset/1/attributes/RowNum"
+        attribute_url = f"http://localhost:9100/api/versioned/v1/{relative_id}"
+        snoop_dict = {}
+        responses.add_callback(
+            responses.PUT, attribute_url, partial(create_callback, snoop=snoop_dict)
+        )
+        attribute = Attribute(self.tamr, self._attributes_json[0], relative_id)
+
+        temp_spec = attribute.spec()
+        new_attribute = temp_spec.with_description(
+            self._updated_attribute_json["description"]
+        ).put()
+        self.assertEqual(new_attribute.name, self._updated_attribute_json["name"])
+        self.assertEqual(
+            new_attribute.description, self._updated_attribute_json["description"]
+        )
+
+        self.assertEqual(
+            json.loads(snoop_dict["payload"]), self._updated_attribute_json
+        )
+
+        self.assertEqual(attribute.name, self._attributes_json[0]["name"])
+        self.assertEqual(attribute.description, self._attributes_json[0]["description"])
+
+        # checking that intermediate didn't change
+        self.assertEqual(
+            temp_spec.to_dict()["description"], self._attributes_json[0]["description"]
+        )
+
     _dataset_json = {
         "id": "unify://unified-data/v1/datasets/1",
         "externalId": "number 1",
@@ -173,3 +210,10 @@ def test_delete_attribute(self):
             "isNullable": False,
         },
     ]
+
+    _updated_attribute_json = {
+        "name": "RowNum",
+        "description": "Synthetic row number updated",
+        "type": {"baseType": "STRING", "attributes": []},
+        "isNullable": False,
+    }