fix issue where using the index to query graphs could throw unexpecte…

…d KeyErrors

LemonGraph/collection.py

@@ -66,6 +66,7 @@ def idx_users(self, obj):
 
 class StatusIndex(object):
     domain = 'status'
+    null = Serializer.null()
 
     def __init__(self, ctx):
         self.ctx = ctx
@@ -90,7 +91,7 @@ def _index(self, idx):
         try:
             return self._indexes[idx]
         except KeyError:
-            self._indexes[idx] = self.ctx.txn.sset('lg.collection.idx.%s.%s' % (self.domain, idx))
+            self._indexes[idx] = self.ctx.txn.sset('lg.collection.idx.%s.%s' % (self.domain, idx), serialize_value=self.null)
         return self._indexes[idx]
 
     def search(self, idx, value):
@@ -101,7 +102,7 @@ def search(self, idx, value):
         except KeyError:
             return
         for key in index.iterpfx(pfx=crc):
-            uuid = key[crclen:]
+            uuid = key[crclen:].decode()
             status = self.ctx.statusDB[uuid]
             if check(status):
                 yield uuid, status

LemonGraph/serializer.py

@@ -44,6 +44,8 @@ def unpack_from_wrapper(*args, **kwargs):
 # for node/edge types/values as well as property keys, you should strive to make sure the encoder is deterministic
 # if you plan to use complex values - if dicts are involved, msgpack is not so much.
 
+def identity(x):
+    return x
 
 class Serializer(object):
     @staticmethod
@@ -99,6 +101,10 @@ def decode(b):
 
         return Serializer(encode=encode, decode=decode)
 
+    @classmethod
+    def null(cls):
+        return Serializer(encode=identity, decode=identity)
+
     @classmethod
     def uints(cls, count, decode_type=tuple, string=False):
         if string: