STYLE: string formatting in test-expressions.py for issue 29886 (pandas-dev#30321)

Author: AncientRickles

pandas/tests/test_expressions.py

@@ -261,9 +261,9 @@ def testit():
     def test_bool_ops_raise_on_arithmetic(self, op_str, opname):
         df = DataFrame({"a": np.random.rand(10) > 0.5, "b": np.random.rand(10) > 0.5})
 
-        msg = "operator %r not implemented for bool dtypes"
+        msg = f"operator {repr(op_str)} not implemented for bool dtypes"
         f = getattr(operator, opname)
-        err_msg = re.escape(msg % op_str)
+        err_msg = re.escape(msg)
 
         with pytest.raises(NotImplementedError, match=err_msg):
             f(df, df)