Python: adds LSET command

CHANGELOG.md

@@ -27,6 +27,7 @@
 * Python: Added LMPOP and BLMPOP commands ([#1547](https://github.com/aws/glide-for-redis/pull/1547))
 * Python: Added MSETNX command ([#1565](https://github.com/aws/glide-for-redis/pull/1565))
 * Python: Added MOVE command ([#1566](https://github.com/aws/glide-for-redis/pull/1566))
+* Python: Added LSET command ([#1584](https://github.com/aws/glide-for-redis/pull/1584))
 * Node: Added OBJECT IDLETIME command ([#1567](https://github.com/aws/glide-for-redis/pull/1567))
 * Node: Added OBJECT REFCOUNT command ([#1568](https://github.com/aws/glide-for-redis/pull/1568))
 * Python: Added SETBIT command ([#1571](https://github.com/aws/glide-for-redis/pull/1571))

python/python/glide/async_commands/core.py

@@ -1415,6 +1415,33 @@ async def lindex(
             await self._execute_command(RequestType.LIndex, [key, str(index)]),
         )
 
+    async def lset(self, key: str, index: int, element: str) -> TOK:
+        """
+        Sets the list element at `index` to `element`.
+
+        The index is zero-based, so `0` means the first element, `1` the second element and so on.
+        Negative indices can be used to designate elements starting at the tail of the list.
+        Here, `-1` means the last element, `-2` means the penultimate and so forth.
+
+        See https://valkey.io/commands/lset/ for details.
+
+        Args:
+            key (str): The key of the list.
+            index (int): The index of the element in the list to be set.
+            element (str): The new element to set at the specified index.
+
+        Returns:
+            TOK: A simple `OK` response.
+
+        Examples:
+            >>> await client.lset("testKey", 1, "two")
+                OK
+        """
+        return cast(
+            TOK,
+            await self._execute_command(RequestType.LSet, [key, str(index), element]),
+        )
+
     async def rpush(self, key: str, elements: List[str]) -> int:
         """
         Inserts all the specified values at the tail of the list stored at `key`.

python/python/glide/async_commands/transaction.py

@@ -924,6 +924,26 @@ def lindex(
         """
         return self.append_command(RequestType.LIndex, [key, str(index)])
 
+    def lset(self: TTransaction, key: str, index: int, element: str) -> TTransaction:
+        """
+        Sets the list element at `index` to `element`.
+
+        The index is zero-based, so `0` means the first element, `1` the second element and so on.
+        Negative indices can be used to designate elements starting at the tail of the list.
+        Here, `-1` means the last element, `-2` means the penultimate and so forth.
+
+        See https://valkey.io/commands/lset/ for details.
+
+        Args:
+            key (str): The key of the list.
+            index (int): The index of the element in the list to be set.
+            element (str): The new element to set at the specified index.
+
+        Commands response:
+            TOK: A simple `OK` response.
+        """
+        return self.append_command(RequestType.LSet, [key, str(index), element])
+
     def rpush(self: TTransaction, key: str, elements: List[str]) -> TTransaction:
         """Inserts all the specified values at the tail of the list stored at `key`.
         `elements` are inserted one after the other to the tail of the list, from the leftmost element

python/python/tests/test_async_client.py

@@ -1352,6 +1352,36 @@ async def endless_blmove_call():
         with pytest.raises(asyncio.TimeoutError):
             await asyncio.wait_for(endless_blmove_call(), timeout=3)
 
+    @pytest.mark.parametrize("cluster_mode", [True, False])
+    @pytest.mark.parametrize("protocol", [ProtocolVersion.RESP2, ProtocolVersion.RESP3])
+    async def test_lset(self, redis_client: TRedisClient):
+        key = get_random_string(10)
+        element = get_random_string(5)
+        values = [get_random_string(5) for _ in range(4)]
+
+        # key does not exist
+        with pytest.raises(RequestError):
+            await redis_client.lset("non_existing_key", 0, element)
+
+        # pushing elements to list
+        await redis_client.lpush(key, values) == 4
+
+        # index out of range
+        with pytest.raises(RequestError):
+            await redis_client.lset(key, 10, element)
+
+        # assert lset result
+        assert await redis_client.lset(key, 0, element) == OK
+
+        values = [element] + values[:-1][::-1]
+        assert await redis_client.lrange(key, 0, -1) == values
+
+        # assert lset with a negative index for the last element in the list
+        assert await redis_client.lset(key, -1, element) == OK
+
+        values[-1] = element
+        assert await redis_client.lrange(key, 0, -1) == values
+
     @pytest.mark.parametrize("cluster_mode", [True, False])
     @pytest.mark.parametrize("protocol", [ProtocolVersion.RESP2, ProtocolVersion.RESP3])
     async def test_sadd_srem_smembers_scard(self, redis_client: TRedisClient):

python/python/tests/test_transaction.py

@@ -217,6 +217,8 @@ async def transaction_test(
     args.append([key9, value3])
     transaction.brpop([key9], 1)
     args.append([key9, value])
+    transaction.lset(key9, 0, value2)
+    args.append(OK)
 
     transaction.sadd(key7, ["foo", "bar"])
     args.append(2)