BUG: ValueError when printing a DataFrame with DataFrame in its attrs

pandas/io/formats/format.py

@@ -669,9 +669,9 @@ def _truncate_horizontally(self) -> None:
         assert self.max_cols_fitted is not None
         col_num = self.max_cols_fitted // 2
         if col_num >= 1:
-            left = self.tr_frame.iloc[:, :col_num]
-            right = self.tr_frame.iloc[:, -col_num:]
-            self.tr_frame = concat((left, right), axis=1)
+            _len = len(self.tr_frame.columns)
+            _slice = np.hstack([np.arange(col_num), np.arange(_len - col_num, _len)])
+            self.tr_frame = self.tr_frame.iloc[:, _slice]
 
             # truncate formatter
             if isinstance(self.formatters, (list, tuple)):
@@ -682,7 +682,7 @@ def _truncate_horizontally(self) -> None:
         else:
             col_num = cast(int, self.max_cols)
             self.tr_frame = self.tr_frame.iloc[:, :col_num]
-        self.tr_col_num = col_num
+        self.tr_col_num: int = col_num
 
     def _truncate_vertically(self) -> None:
         """Remove rows, which are not to be displayed.

pandas/tests/io/formats/test_format.py

@@ -129,6 +129,13 @@ def test_repr_truncation_preserves_na(self):
         with option_context("display.max_rows", 2, "display.show_dimensions", False):
             assert repr(df) == "       a\n0   <NA>\n..   ...\n9   <NA>"
 
+    def test_repr_truncation_dataframe_attrs(self):
+        # 60455
+        df = DataFrame([[0] * 10])
+        df.attrs["b"] = DataFrame([])
+        with option_context("display.max_columns", 2, "display.show_dimensions", False):
+            assert repr(df) == "   0  ...  9\n0  0  ...  0"
+
     def test_max_colwidth_negative_int_raises(self):
         # Deprecation enforced from:
         # https://github.com/pandas-dev/pandas/issues/31532