diff --git a/ome_zarr/csv.py b/ome_zarr/csv.py
index 01601ea7..6cea603d 100644
--- a/ome_zarr/csv.py
+++ b/ome_zarr/csv.py
@@ -19,7 +19,7 @@ def parse_csv_value(value: str, col_type: str) -> str | float | int | bool:
         if col_type == "d":
             rv = float(value)
         elif col_type == "l":
-            rv = int(round(float(value)))
+            rv = round(float(value))
         elif col_type == "b":
             rv = bool(value)
     except ValueError:
diff --git a/ome_zarr/io.py b/ome_zarr/io.py
index b49f50a0..3a4d2fd2 100644
--- a/ome_zarr/io.py
+++ b/ome_zarr/io.py
@@ -134,7 +134,7 @@ def basename(self) -> str:
         >>> ZarrLocation("https://example.com/baz/").basename()
         'baz'
         """
-        path = self.__path.endswith("/") and self.__path[0:-1] or self.__path
+        path = (self.__path.endswith("/") and self.__path[0:-1]) or self.__path
         return path.split("/")[-1]
 
     # TODO: update to from __future__ import annotations with 3.7+
diff --git a/ome_zarr/writer.py b/ome_zarr/writer.py
index e327e463..78631fa3 100644
--- a/ome_zarr/writer.py
+++ b/ome_zarr/writer.py
@@ -28,7 +28,7 @@ def _get_valid_axes(
     ndim: int | None = None,
     axes: str | list[str] | list[dict[str, str]] | None = None,
     fmt: Format = CurrentFormat(),
-) -> None | list[str] | list[dict[str, str]]:
+) -> list[str] | list[dict[str, str]] | None:
     """Returns list of axes valid for fmt.version or raise exception if invalid"""
 
     if fmt.version in ("0.1", "0.2"):
diff --git a/tests/test_reader.py b/tests/test_reader.py
index 67d69f4f..86188a0e 100644
--- a/tests/test_reader.py
+++ b/tests/test_reader.py
@@ -36,7 +36,7 @@ def test_label(self):
 
     def test_omero(self):
         reader = Reader(parse_url(str(self.path)))()
-        image_node = list(reader)[0]
+        image_node = next(iter(reader))
         omero = image_node.zarr.root_attrs.get("omero")
         assert "channels" in omero
         assert isinstance(omero["channels"], list)
diff --git a/tests/test_upgrade.py b/tests/test_upgrade.py
index cda9bfb7..7c01476d 100644
--- a/tests/test_upgrade.py
+++ b/tests/test_upgrade.py
@@ -29,7 +29,7 @@ def assert_data(self, path, shape, fmt, mode="r"):
         loc = parse_url(path, mode=mode, fmt=fmt)
         assert loc
         reader = Reader(loc)
-        node = list(reader())[0]
+        node = next(iter(reader()))
         assert Multiscales.matches(node.zarr)
         assert node.data[0].shape == shape
         assert np.max(node.data[0]) > 0
diff --git a/tests/test_writer.py b/tests/test_writer.py
index 753963ea..a396ca6e 100644
--- a/tests/test_writer.py
+++ b/tests/test_writer.py
@@ -108,7 +108,7 @@ def test_writer(
 
         # Verify
         reader = Reader(parse_url(f"{self.path}/test"))
-        node = list(reader())[0]
+        node = next(iter(reader()))
         assert Multiscales.matches(node.zarr)
         if version.version in ("0.1", "0.2"):
             # v0.1 and v0.2 MUST be 5D
@@ -136,7 +136,7 @@ def test_write_image_current(self, array_constructor):
         data = array_constructor(data)
         write_image(data, self.group, axes="zyx")
         reader = Reader(parse_url(f"{self.path}/test"))
-        image_node = list(reader())[0]
+        image_node = next(iter(reader()))
         for transfs in image_node.metadata["coordinateTransformations"]:
             assert len(transfs) == 1
             assert transfs[0]["type"] == "scale"
@@ -186,7 +186,7 @@ def test_write_image_dask(self, read_from_zarr, compute):
             dask_delayed_jobs = persist(*dask_delayed_jobs)
 
         reader = Reader(parse_url(f"{self.path}/test"))
-        image_node = list(reader())[0]
+        image_node = next(iter(reader()))
         first_chunk = [c[0] for c in image_node.data[0].chunks]
         assert tuple(first_chunk) == _retuple(chunks, image_node.data[0].shape)
         for level, transfs in enumerate(
@@ -1069,7 +1069,7 @@ def scaler(self, request):
     def verify_label_data(self, label_name, label_data, fmt, shape, transformations):
         # Verify image data
         reader = Reader(parse_url(f"{self.path}/labels/{label_name}"))
-        node = list(reader())[0]
+        node = next(iter(reader()))
         assert Multiscales.matches(node.zarr)
         if fmt.version in ("0.1", "0.2"):
             # v0.1 and v0.2 MUST be 5D