flake8 ignore E203

.flake8

@@ -2,14 +2,17 @@
 # see https://flake8.pycqa.org/en/latest/user/options.html
 
 [flake8]
+# E203 is not PEP8 compliant https://black.readthedocs.io/en/stable/the_black_code_style/current_style.html#slices
+# Is excluded from flake8's own config https://flake8.pycqa.org/en/latest/user/configuration.html
+extend-ignore = E203
 max-line-length = 99
 max-doc-length = 99
 per-file-ignores =
     # rdtools.x.y imported but unused
     __init__.py:F401
     # invalid escape sequence '\s'
     versioneer.py:W605
-exclude = 
+exclude =
     docs
     .eggs
     build

rdtools/test/interpolate_test.py

@@ -145,7 +145,7 @@ def test_interpolate_warning(test_df, df_target_index, df_expected_result):
     N = len(test_df)
     all_idx = list(range(N))
     # drop every other value in the first third of the dataset
-    index_with_gaps = all_idx[: N // 3][::2] + all_idx[N // 3 :]
+    index_with_gaps = all_idx[: N // 3][::2] + all_idx[N // 3:]
     test_df = test_df.iloc[index_with_gaps, :]
     with pytest.warns(UserWarning):
         interpolate(