fix format

pandas/tests/reshape/concat/test_index.py

@@ -334,17 +334,15 @@ def test_concat_with_key_not_unique(self):
         df_a = concat([df1, df2, df3], keys=["x", "y", "x"])
         # the warning is caused by indexing unsorted multi-index
         with tm.assert_produces_warning(
-            PerformanceWarning,
-            match="indexing past lexsort depth"
+            PerformanceWarning, match="indexing past lexsort depth"
         ):
             out_a = df_a.loc[("x", 0), :]
 
         df_b = DataFrame(
             {"name": [1, 2, 3]}, index=Index([("x", 0), ("y", 0), ("x", 0)])
         )
         with tm.assert_produces_warning(
-            PerformanceWarning,
-            match="indexing past lexsort depth"
+            PerformanceWarning, match="indexing past lexsort depth"
         ):
             out_b = df_b.loc[("x", 0)]
 
@@ -355,8 +353,7 @@ def test_concat_with_key_not_unique(self):
         df3 = DataFrame({"name": ["c", "d"]})
         df_a = concat([df1, df2, df3], keys=["x", "y", "x"])
         with tm.assert_produces_warning(
-            PerformanceWarning,
-            match="indexing past lexsort depth"
+            PerformanceWarning, match="indexing past lexsort depth"
         ):
             out_a = df_a.loc[("x", 0), :]
 
@@ -369,8 +366,7 @@ def test_concat_with_key_not_unique(self):
         ).set_index(["a", "b"])
         df_b.index.names = [None, None]
         with tm.assert_produces_warning(
-            PerformanceWarning,
-            match="indexing past lexsort depth"
+            PerformanceWarning, match="indexing past lexsort depth"
         ):
             out_b = df_b.loc[("x", 0), :]