CLN: Deprecate non-keyword arguments in concat pandas-dev#41485

pandas/tests/reshape/concat/test_concat.py

@@ -642,16 +642,15 @@ def test_concat_multiindex_with_empty_rangeindex():
 
 def test_concat_posargs_deprecation(all_parsers):
     # https://github.com/pandas-dev/pandas/issues/41485
-    df = pd.DataFrame([[1,2,3]], index=["a"])
-    df2 = pd.DataFrame([[4,5,6]], index=["b"])
+    df = pd.DataFrame([[1, 2, 3]], index=["a"])
+    df2 = pd.DataFrame([[4, 5, 6]], index=["b"])
 
     msg = (
         "In a future version of pandas all arguments of concat"
         "except for the argument 'objs' will be keyword-only"
     )
     with tm.assert_produces_warning(FutureWarning, match=msg):
-       result = concat([df, df2], " ")
-    expected = DataFrame([[1,2,3],[4,5,6]], index=["a","b"])
+        result = concat([df, df2], " ")
+    expected = DataFrame([[1, 2, 3],[4, 5, 6]], index=["a", "b"])
     tm.assert_frame_equal(result, expected)
-