diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index e873a16..3f205a1 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -11,13 +11,13 @@ repos:
       - id: trailing-whitespace
   # Python
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.15.20
+    rev: v0.16.6
     hooks:
         # lint
       - id: ruff-check
         # format
       - id: ruff-format
   - repo: https://github.com/astral-sh/uv-pre-commit
-    rev: 0.11.25
+    rev: 0.12.10
     hooks:
       - id: uv-lock
diff --git a/docs/quickstart_for_tidybayes_users.md b/docs/quickstart_for_tidybayes_users.md
index 868b727..caad1c4 100644
--- a/docs/quickstart_for_tidybayes_users.md
+++ b/docs/quickstart_for_tidybayes_users.md
@@ -13,7 +13,6 @@ import polarbayes as pb
 
 pb.spread_draws(data, var_names=["var1", "var2"])
 pb.gather_draws(data, var_names=["var1", "var2"])
-
 ```
 
 Or provide no `var_names` to spread or gather all available variables:
@@ -58,7 +57,7 @@ draws <- mcmc_output |> spread_draws(x1[time], x2[time, location])
 might become this PolarBayes Python code:
 
 ```python
-draws = pb.spread_draws(mcmc_output_arviz, var_names = ["x1", "x2"])
+draws = pb.spread_draws(mcmc_output_arviz, var_names=["x1", "x2"])
 ```
 
 The PolarBayes output will still have `time` and `location` columns along with the MCMC sample ID columns, provided those are the names of the dimensions in the `mcmc_output_arviz` [`xarray.DataTree`][] object. If the dimension names in your [`xarray.DataTree`][] object are not the ones you want in your output data frame, you can simply rename them via [`polars.DataFrame.rename`][].
diff --git a/polarbayes/__init__.py b/polarbayes/__init__.py
index cf3b685..6c8b120 100644
--- a/polarbayes/__init__.py
+++ b/polarbayes/__init__.py
@@ -2,8 +2,8 @@
 from polarbayes.spread import spread_draws, spread_draws_and_get_index_cols
 
 __all__ = [
+    "gather_draws",
+    "gather_variables",
     "spread_draws",
     "spread_draws_and_get_index_cols",
-    "gather_variables",
-    "gather_draws",
 ]
diff --git a/polarbayes/gather.py b/polarbayes/gather.py
index 21406e9..120f956 100644
--- a/polarbayes/gather.py
+++ b/polarbayes/gather.py
@@ -1,5 +1,4 @@
-from collections.abc import Sequence
-from typing import Iterable
+from collections.abc import Iterable, Sequence
 
 import arviz_base as az
 import numpy as np
@@ -51,7 +50,6 @@ def _assert_not_in_index_columns(
             f"in the input data frame. Either specify a different "
             f" {arg_name} or rename the index column named '{arg_value}'."
         )
-    return None
 
 
 def gather_variables(
diff --git a/polarbayes/schema.py b/polarbayes/schema.py
index 12bf18e..ae15533 100644
--- a/polarbayes/schema.py
+++ b/polarbayes/schema.py
@@ -2,7 +2,7 @@
 Column order schemas for polarbayes output
 """
 
-from typing import Iterable
+from collections.abc import Iterable
 
 # default and reserved column names
 CHAIN_NAME = "chain"
diff --git a/polarbayes/spread.py b/polarbayes/spread.py
index 2b7300c..360927e 100644
--- a/polarbayes/spread.py
+++ b/polarbayes/spread.py
@@ -1,4 +1,4 @@
-from typing import Iterable
+from collections.abc import Iterable
 
 import arviz_base as az
 import numpy as np
diff --git a/test/test_gather.py b/test/test_gather.py
index 6b14da6..f05b91f 100644
--- a/test/test_gather.py
+++ b/test/test_gather.py
@@ -7,9 +7,9 @@
 import pytest
 
 from polarbayes.gather import (
+    _assert_not_in_index_columns,
     gather_draws,
     gather_variables,
-    _assert_not_in_index_columns,
 )
 from polarbayes.schema import CHAIN_NAME, DRAW_NAME, VALUE_NAME, VARIABLE_NAME
 
diff --git a/test/test_spread.py b/test/test_spread.py
index 6cd3e17..279c47e 100644
--- a/test/test_spread.py
+++ b/test/test_spread.py
@@ -1,16 +1,15 @@
 import arviz_base as az
 import numpy as np
-import pytest
 import pandas as pd
 import polars as pl
 import polars.selectors as cs
+import pytest
 
-from polarbayes.schema import order_index_column_names, CHAIN_NAME, DRAW_NAME
-
+from polarbayes.schema import CHAIN_NAME, DRAW_NAME, order_index_column_names
 from polarbayes.spread import (
-    spread_draws_to_pandas_,
     spread_draws,
     spread_draws_and_get_index_cols,
+    spread_draws_to_pandas_,
 )
 
 eight_schools_data = az.load_arviz_data("non_centered_eight")