Updated tests, added a priority queue

Updated the tests to reflect the functionality added in verion 0.4.0, and then
updated the library to actually pass all those tests. Notably, there was a
problem with loading and dumping to and from files, but it's been resolved.

This version also sees the introduction of a priority queue, with unique elements.
While it is potentially problematic to be tied to the uniqueness constraing,
one can always inject arbitrary ids for repeated values. Perhaps not the most
efficient method in the world, but it exposes one more list type in redis.

qr.py

@@ -69,7 +69,7 @@ def __len__(self):
     def __getitem__(self, val):
         """Get a slice or a particular index."""
         try:
-            return [self._unpack(i) for i in self.redis.lrange(self.key, val.start, val.stop)]
+            return [self._unpack(i) for i in self.redis.lrange(self.key, val.start, val.stop - 1)]
         except AttributeError:
             return self._unpack(self.redis.lindex(self.key, val))
         except Exception as e:
@@ -96,10 +96,11 @@ def dump(self, fobj):
 
     def load(self, fobj):
         """Load the contents of the provided fobj into the queue"""
-        next = self.serializer.load(obj)
-        while next:
-            self.redis.lpush(self._pack(next))
-            next = self.serializer.load(fobj)
+        try:
+            while True:
+                self.redis.lpush(self.key, self._pack(self.serializer.load(fobj)))
+        except:
+            return
 
     def dumpfname(self, fname, truncate=False):
         """Destructively dump the contents of the queue into fname"""
@@ -128,11 +129,15 @@ def peek(self):
 
     def elements(self):
         """Return all elements as a Python list"""
-        return self.redis.lrange(self.key, 0, -1)
+        return [self._unpack(o) for o in self.redis.lrange(self.key, 0, -1)]
 
     def elements_as_json(self):
         """Return all elements as JSON object"""
         return json.dumps(self.elements)
+
+    def clear(self):
+        """Removes all the elements in the queue"""
+        self.redis.delete(self.key)
 
 class Deque(BaseQueue):
     """Implements a double-ended queue"""
@@ -191,7 +196,7 @@ def __len__(self):
     def __getitem__(self, val):
         """Get a slice or a particular index."""
         try:
-            return [self._unpack(i) for i in self.redis.zrange(self.key, val.start, val.stop)]
+            return [self._unpack(i) for i in self.redis.zrange(self.key, val.start, val.stop - 1)]
         except AttributeError:
             val = self.redis.zrange(self.key, val, val)
             if val:
@@ -206,16 +211,18 @@ def dump(self, fobj):
         next = self.redis.zrange(self.key, 0, 0, withscores=True)
         removed = self.redis.zremrangebyrank(self.key, 0, 0)
         while next:
-            fobj.write(next[0])
-            next = self.redis.zrange(self.key, 0, 0)
+            self.serializer.dump(next[0], fobj)
+            next = self.redis.zrange(self.key, 0, 0, withscores=True)
             removed = self.redis.zremrangebyrank(self.key, 0, 0)
 
     def load(self, fobj):
         """Load the contents of the provided fobj into the queue"""
-        next = self.serializer.load(fobj)
-        while next:
-            self.redis.zadd(self.key, self.serializer._pack(*next))
-            next = self.serializer.load(fobj)
+        try:
+            while True:
+                value, score = self.serializer.load(fobj)
+                self.redis.zadd(self.key, value, score)
+        except Exception as e:
+            return
 
     def dumpfname(self, fname, truncate=False):
         """Destructively dump the contents of the queue into fname"""
@@ -244,7 +251,7 @@ def peek(self, withscores=False):
 
     def elements(self):
         """Return all elements as a Python list"""
-        return self.redis.zrange(self.key, 0, -1)
+        return [self._unpack(o) for o in self.redis.zrange(self.key, 0, -1)]
 
     def pop(self, withscores=False):
         '''Get the element with the lowest score, and pop it off'''
@@ -313,4 +320,3 @@ def pop(self):
         popped = self.redis.lpop(self.key)
         log.debug('Popped ** %s ** from key ** %s **' % (popped, self.key))
         return self._unpack(popped)
-