import pytest from pandas import Index import pandas._testing as tm def test_add_prefix_suffix(float_frame): with_prefix = float_frame.add_prefix("foo#") expected = Index([f"foo#{c}" for c in float_frame.columns]) tm.assert_index_equal(with_prefix.columns, expected) with_suffix = float_frame.add_suffix("#foo") expected = Index([f"{c}#foo" for c in float_frame.columns]) tm.assert_index_equal(with_suffix.columns, expected) with_pct_prefix = float_frame.add_prefix("%") expected = Index([f"%{c}" for c in float_frame.columns]) tm.assert_index_equal(with_pct_prefix.columns, expected) with_pct_suffix = float_frame.add_suffix("%") expected = Index([f"{c}%" for c in float_frame.columns]) tm.assert_index_equal(with_pct_suffix.columns, expected) def test_add_prefix_suffix_axis(float_frame): # GH 47819 with_prefix = float_frame.add_prefix("foo#", axis=0) expected = Index([f"foo#{c}" for c in float_frame.index]) tm.assert_index_equal(with_prefix.index, expected) with_prefix = float_frame.add_prefix("foo#", axis=1) expected = Index([f"foo#{c}" for c in float_frame.columns]) tm.assert_index_equal(with_prefix.columns, expected) with_pct_suffix = float_frame.add_suffix("#foo", axis=0) expected = Index([f"{c}#foo" for c in float_frame.index]) tm.assert_index_equal(with_pct_suffix.index, expected) with_pct_suffix = float_frame.add_suffix("#foo", axis=1) expected = Index([f"{c}#foo" for c in float_frame.columns]) tm.assert_index_equal(with_pct_suffix.columns, expected) def test_add_prefix_suffix_invalid_axis(float_frame): with pytest.raises(ValueError, match="No axis named 2 for object type DataFrame"): float_frame.add_prefix("foo#", axis=2) with pytest.raises(ValueError, match="No axis named 2 for object type DataFrame"): float_frame.add_suffix("foo#", axis=2)