bidict/docs/other-functionality.rst

.. _other-functionality:

Other Functionality
===================

:func:`bidict.pairs`
--------------------

:func:`bidict.pairs` has the same signature as ``dict.__init__()``.
It yields the given (*k*, *v*) pairs
in the same order they'd be processed
if passed into ``dict.__init__()``.

    >>> from bidict import pairs
    >>> list(pairs({'a': 1}, b=2))
    [('a', 1), ('b', 2)]
    >>> list(pairs([('a', 1), ('b', 2)], b=3))
    [('a', 1), ('b', 2), ('b', 3)]


:func:`bidict.inverted`
-----------------------

bidict provides the :class:`~bidict.inverted` iterator
to help you get inverse pairs from various types of objects.

Pass in a mapping to get the inverse mapping::

    >>> from bidict import inverted
    >>> it = inverted({1: 'one'})
    >>> {k: v for (k, v) in it}
    {'one': 1}

...an iterable of pairs to get the pairs' inverses::

    >>> list(inverted([(1, 'one'), (2, 'two')]))
    [('one', 1), ('two', 2)]
    >>> list(inverted((i*i, i) for i in range(2, 5)))
    [(2, 4), (3, 9), (4, 16)]

...or any object implementing an ``__inverted__`` method,
which objects that already know their own inverses (such as bidicts)
can implement themselves::

    >>> from bidict import bidict, OrderedBidict
    >>> dict(inverted(bidict({1: 'one'})))
    {'one': 1}
    >>> list(inverted(OrderedBidict([(2, 4), (3, 9)])))
    [(4, 2), (9, 3)]


Perhaps you'd be interested in having a look at the
:ref:`addendum` next.