values with scores of 0 were previously failing due to the way the callback converted values. changed to a separate function to get proper handling. fixes #33

2 files changed, 19 insertions, 5 deletions

diff --git a/redis/client.py b/redis/client.py
index d29df67..28dbf46 100644
--- a/redis/client.py
+++ b/redis/client.py
@@ -178,6 +178,17 @@ def zset_score_pairs(response, **options):
         return response
     return zip(response[::2], map(float, response[1::2]))
 
+def int_or_none(response):
+    if response is None:
+        return None
+    return int(response)
+
+def float_or_none(response):
+    if response is None:
+        return None
+    return float(response)
+
+
 class Redis(threading.local):
     """
     Implementation of the Redis protocol.
@@ -196,7 +207,7 @@ class Redis(threading.local):
             ),
         string_keys_to_dict(
             'DECRBY HLEN INCRBY LLEN SCARD SDIFFSTORE SINTERSTORE '
-            'SUNIONSTORE ZCARD ZRANK ZREMRANGEBYSCORE ZREVRANK',
+            'SUNIONSTORE ZCARD ZREMRANGEBYSCORE ZREVRANK',
             int
             ),
         string_keys_to_dict(
@@ -204,8 +215,7 @@ class Redis(threading.local):
             'LPUSH RPUSH',
             lambda r: isinstance(r, int) and r or r == 'OK'
             ),
-        string_keys_to_dict('ZSCORE ZINCRBY',
-            lambda r: r is not None and float(r) or r),
+        string_keys_to_dict('ZSCORE ZINCRBY', float_or_none),
         string_keys_to_dict(
             'FLUSHALL FLUSHDB LSET LTRIM MSET RENAME '
             'SAVE SELECT SET SHUTDOWN',
@@ -225,6 +235,7 @@ class Redis(threading.local):
             'PING': lambda r: r == 'PONG',
             'RANDOMKEY': lambda r: r and r or None,
             'TTL': lambda r: r != -1 and r or None,
+            'ZRANK': int_or_none,
         }
         )
 
diff --git a/tests/server_commands.py b/tests/server_commands.py
index da20a97..b827bf3 100644
--- a/tests/server_commands.py
+++ b/tests/server_commands.py
@@ -684,6 +684,8 @@ class ServerCommandsTestCase(unittest.TestCase):
         self.assertEquals(self.client.zrank('a', 'a3'), 2)
         self.assertEquals(self.client.zrank('a', 'a4'), 3)
         self.assertEquals(self.client.zrank('a', 'a5'), 4)
+        # non-existent value in zset
+        self.assertEquals(self.client.zrank('a', 'a6'), None)
 
     def test_zrem(self):
         # key is not a zset
@@ -746,8 +748,9 @@ class ServerCommandsTestCase(unittest.TestCase):
         self.assertRaises(redis.ResponseError, self.client.zscore, 'a', 'a1')
         del self.client['a']
         # real logic
-        self.make_zset('a', {'a1': 1, 'a2': 2, 'a3': 3})
-        self.assertEquals(self.client.zscore('a', 'a2'), 2.0)
+        self.make_zset('a', {'a1': 0, 'a2': 1, 'a3': 2})
+        self.assertEquals(self.client.zscore('a', 'a1'), 0.0)
+        self.assertEquals(self.client.zscore('a', 'a2'), 1.0)
         # test a non-existant member
         self.assertEquals(self.client.zscore('a', 'a4'), None)