` is
undefined an empty iterator is returned.

This filter is useful if you expect the template to be rendered with
an implementation of Jinja in another programming language that does
not have a ``.items()`` method on its mapping type.

.. code-block:: html+jinja

    <dl>
    {% for key, value in my_dict|items %}
        <dt>{{ key }}
        <dd>{{ value }}
    {% endfor %}
    </dl>

.. versionadded:: 3.1
Nz'Can only get item pairs from a mapping.)