diff --git a/tests/test_single_obs_key.py b/tests/test_single_obs_key.py
index 8dda5d2..16e4a97 100644
--- a/tests/test_single_obs_key.py
+++ b/tests/test_single_obs_key.py
@@ -41,4 +41,4 @@ def test_single_entry_calc(tmp_path):
     io.extend([water for _ in range(5)])
     assert len(io) == 6
     assert len(io[:]) == 6
-    assert len(list(io)) == 6
\ No newline at end of file
+    assert len(list(io)) == 6