New dependency: fuzzywuzzy.

We now have a fuzzy matching method for tags. It comes at the cost of
another dependency, but it's pure python, and could come in real handy
when doing filterings on tags when you have a couple variations of
essentially the same stupid thing.

setup.py

@@ -19,5 +19,5 @@
       scripts=[],
       license='BSD',
       long_description=open('README.rst').read(),
-      install_requires=['asciitree', 'pathlib', 'scandir', 'six']
+      install_requires=['asciitree', 'pathlib', 'scandir', 'six', 'fuzzywuzzy']
       )

src/datreant/core/agglimbs.py

@@ -6,6 +6,8 @@
 """
 from six import string_types, with_metaclass
 
+from fuzzywuzzy import process
+
 from . import filesystem
 from . import _AGGTREELIMBS, _AGGLIMBS
 from .collections import Bundle
@@ -57,10 +59,10 @@ def __init__(self, collection):
         super(AggTags, self).__init__(collection)
 
     def __repr__(self):
-        return "<AggTags({})>".format(self.all)
+        return "<AggTags({})>".format(list(self.all))
 
     def __str__(self):
-        tags = self.all
+        tags = list(self.all)
         agg = "Tags"
         majsep = "="
         seplength = len(agg)
@@ -134,6 +136,46 @@ def clear(self):
         for member in self._collection:
             member.tags.clear()
 
+    def fuzzy(self, tag, threshold=80, scope='all'):
+        """Get a tuple of existing tags that fuzzily match a given one.
+
+        Parameters
+        ----------
+        tags : str or list
+            Tag or tags to get fuzzy matches for.
+        threshold : int
+            Lowest match score to return. Setting to 0 will return every tag,
+            while setting to 100 will return only exact matches.
+        scope : {'all', 'any'}
+            Tags to use. 'all' will use only tags found within all Treants in
+            collection, while 'any' will use tags found within at least one
+            Treant in collection.
+
+        Returns
+        -------
+        matches : tuple
+            Tuple of tags that match.
+        """
+        if isinstance(tag, string_types):
+            tags = [tag]
+        else:
+            tags = tag
+
+        if scope == 'all':
+            choices = self.all
+        elif scope == 'any':
+            choices = self.any
+        else:
+            raise ValueError("Scope can only be 'any' or 'all'")
+
+        matches = []
+
+        for tag in tags:
+            matches += [i[0] for i in process.extract(tag, choices, limit=None)
+                        if i[1] > threshold]
+
+        return tuple(matches)
+
 
 class AggCategories(AggLimb):
     """Interface to categories.

src/datreant/core/limbs.py

@@ -8,6 +8,8 @@
 from six import string_types, with_metaclass
 from collections import defaultdict
 
+from fuzzywuzzy import process
+
 from . import filesystem
 from .collections import Bundle
 from . import _TREELIMBS, _LIMBS
@@ -260,6 +262,35 @@ def clear(self):
         with self._treant._write:
             self._treant._state['tags'] = list()
 
+    def fuzzy(self, tag, threshold=80):
+        """Get a tuple of existing tags that fuzzily match a given one.
+
+        Parameters
+        ----------
+        tags : str or list
+            Tag or tags to get fuzzy matches for.
+        threshold : int
+            Lowest match score to return. Setting to 0 will return every tag,
+            while setting to 100 will return only exact matches.
+
+        Returns
+        -------
+        matches : tuple
+            Tuple of tags that match.
+        """
+        if isinstance(tag, string_types):
+            tags = [tag]
+        else:
+            tags = tag
+
+        matches = []
+
+        for tag in tags:
+            matches += [i[0] for i in process.extract(tag, self, limit=None)
+                        if i[1] > threshold]
+
+        return tuple(matches)
+
 
 class Categories(Limb):
     """Interface to categories.