From 22029107658bd99f51bda53ef1f8ed5e65965d12 Mon Sep 17 00:00:00 2001
From: Niko Aarnio <niko.aarnio@protonmail.com>
Date: Fri, 12 Jan 2024 10:09:06 +0200
Subject: [PATCH] Fix typing for ALR transform

---
 eis_toolkit/transformations/coda/alr.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/eis_toolkit/transformations/coda/alr.py b/eis_toolkit/transformations/coda/alr.py
index dd1008d2..ab880c8c 100644
--- a/eis_toolkit/transformations/coda/alr.py
+++ b/eis_toolkit/transformations/coda/alr.py
@@ -3,7 +3,7 @@
 import numpy as np
 import pandas as pd
 from beartype import beartype
-from beartype.typing import Sequence
+from beartype.typing import Optional, Sequence
 
 from eis_toolkit.exceptions import InvalidColumnException, NumericValueSignException
 from eis_toolkit.utilities.aitchison_geometry import _closure
@@ -19,7 +19,9 @@ def _alr_transform(df: pd.DataFrame, columns: Sequence[str], denominator_column:
 
 
 @beartype
-def alr_transform(df: pd.DataFrame, column: str = None, keep_denominator_column: bool = False) -> pd.DataFrame:
+def alr_transform(
+    df: pd.DataFrame, column: Optional[str] = None, keep_denominator_column: bool = False
+) -> pd.DataFrame:
     """
     Perform an additive logratio transformation on the data.