Add support for ZINTERCARD (redis#1857)

* add zintercard

* fix pr comment

* linters

Author: dvora-h

redis/commands/core.py

@@ -3153,6 +3153,19 @@ def zinterstore(self, dest, keys, aggregate=None):
         """
         return self._zaggregate("ZINTERSTORE", dest, keys, aggregate)
 
+    def zintercard(self, numkeys: int, keys: List[str], limit: int = 0) -> int:
+        """
+        Return the cardinality of the intersect of multiple sorted sets
+        specified by ``keys`.
+        When LIMIT provided (defaults to 0 and means unlimited), if the intersection
+        cardinality reaches limit partway through the computation, the algorithm will
+        exit and yield limit as the cardinality
+
+        For more information check https://redis.io/commands/zintercard
+        """
+        args = [numkeys, *keys, "LIMIT", limit]
+        return self.execute_command("ZINTERCARD", *args)
+
     def zlexcount(self, name, min, max):
         """
         Return the number of items in the sorted set ``name`` between the

tests/test_commands.py

@@ -1979,6 +1979,15 @@ def test_zinter(self, r):
             (b"a1", 23),
         ]
 
+    @pytest.mark.onlynoncluster
+    # @skip_if_server_version_lt("7.0.0") turn on after redis 7 release
+    def test_zintercard(self, unstable_r):
+        unstable_r.zadd("a", {"a1": 1, "a2": 2, "a3": 1})
+        unstable_r.zadd("b", {"a1": 2, "a2": 2, "a3": 2})
+        unstable_r.zadd("c", {"a1": 6, "a3": 5, "a4": 4})
+        assert unstable_r.zintercard(3, ["a", "b", "c"]) == 2
+        assert unstable_r.zintercard(3, ["a", "b", "c"], limit=1) == 1
+
     @pytest.mark.onlynoncluster
     def test_zinterstore_sum(self, r):
         r.zadd("a", {"a1": 1, "a2": 1, "a3": 1})