``pytester`` learned two new functions, `no_fnmatch_line <https://docs.pytest.org/en/latest/reference.html#_pytest.pytester.LineMatcher.no_fnmatch_line>`_ and
`no_re_match_line <https://docs.pytest.org/en/latest/reference.html#_pytest.pytester.LineMatcher.no_re_match_line>`_.

The functions are used to ensure the captured text *does not* match the given
pattern.

The previous idiom was to use ``re.match``:

.. code-block:: python

    assert re.match(pat, result.stdout.str()) is None

Or the ``in`` operator:

.. code-block:: python

    assert text in result.stdout.str()

But the new functions produce best output on failure.