Can now set categories with dict directly.

Can also set all member categories with single dict from Bundle.
Likewise with a list, set, or tags for all member tags from Bundle.

docs/bundles.rst

@@ -271,8 +271,14 @@ And if we access a category with a key that isn't present among all members,
     >>> b.categories['health']
     [None, None, 'good', 'poor']
 
+If we're interested in the values corresponding 
 
 
+Grouping by value
+-----------------
+
+Operating on members in parallel
+================================
 
 API Reference: Bundle
 =====================

docs/tags-categories.rst

@@ -74,6 +74,9 @@ API Reference: Tags
 -------------------
 See the :ref:`Tags_api` API reference for more details.
 
+
+.. _Categories_guide:
+
 Using categories
 ================
 Categories are key-value pairs. They are particularly useful as switches for

src/datreant/core/agglimbs.py

@@ -80,6 +80,18 @@ def __str__(self):
                 out = out + "'{}'\n".format(tags[i])
         return out
 
+    @staticmethod
+    def _setter(self, val):
+        """Used for constructing the property when attaching this Limb to a class.
+
+        """
+        if isinstance(val, (Tags, list, set)):
+            val = list(val)
+            self.tags.clear()
+            self.tags.add(val)
+        else:
+            raise TypeError("Can only set with tags, a list, or set")
+
     def __iter__(self):
         return self.all.__iter__()
 
@@ -294,6 +306,18 @@ def __str__(self):
                 out = out + "'{}': '{}'\n".format(key, value)
         return out
 
+    @staticmethod
+    def _setter(self, val):
+        """Used for constructing the property when attaching this Limb to a class.
+
+        """
+        if isinstance(val, (Categories, dict)):
+            val = dict(val)
+            self.categories.clear()
+            self.categories.add(val)
+        else:
+            raise TypeError("Can only set with categories or dict")
+
     def __getitem__(self, keys):
         """Get values for a given key, list of keys, or set of keys.
 

src/datreant/core/collections.py

@@ -620,6 +620,11 @@ def getter(self):
                 setattr(self, "_"+limb._name, limb(self))
             return getattr(self, "_"+limb._name)
 
+        try:
+            setter = limb._setter
+        except AttributeError:
+            setter = None
+
         # set the property
         setattr(cls, limb._name,
                 property(getter, None, None, limb.__doc__))

src/datreant/core/limbs.py

@@ -114,10 +114,11 @@ def _setter(self, val):
 
         """
         if isinstance(val, (Tags, list, set)):
+            val = list(val)
             self.tags.clear()
-            self.tags.add(list(val))
+            self.tags.add(val)
         else:
-            raise TypeError("Can only set with a list or set")
+            raise TypeError("Can only set with tags, a list, or set")
 
     def __getitem__(self, value):
         with self._treant._read:
@@ -374,6 +375,18 @@ def __str__(self):
                 out = out + "'{}': '{}'\n".format(key, categories[key])
         return out
 
+    @staticmethod
+    def _setter(self, val):
+        """Used for constructing the property when attaching this Limb to a class.
+
+        """
+        if isinstance(val, (Categories, dict)):
+            val = dict(val)
+            self.categories.clear()
+            self.categories.add(val)
+        else:
+            raise TypeError("Can only set with categories or dict")
+
     def __getitem__(self, keys):
         """Get values for given `keys`.
 

src/datreant/core/tests/test_treants.py

@@ -329,6 +329,21 @@ def test_KeyError(self, treant):
             with pytest.raises(KeyError):
                 treant.categories['hello?']
 
+        def test_get_categories(self, treant):
+            treant.categories['bark'] = 'dark'
+            treant.categories['leaves'] = 'many'
+            treant.categories['roots'] = 'shallow'
+
+            # get a single category
+            assert treant.categories['leaves'] == 'many'
+
+            # get multiple categories with list
+            assert treant.categories[['leaves', 'bark']] == ['many', 'dark']
+
+            # get multiple categories with set
+            assert treant.categories[{'leaves', 'bark'}] == {'leaves': 'many',
+                                                             'bark': 'dark'}
+
 
 class TestGroup(TestTreant):
     """Test Group-specific features.