mirror of https://github.com/jab/bidict.git
33 lines
919 B
ReStructuredText
33 lines
919 B
ReStructuredText
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.. _inverted:
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inverted
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========
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bidict provides the :class:`inverted() <bidict.inverted>` iterator
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to help you take the inverse of any kind of object that can be inverted.
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If you've ever worked with the :func:`reversed` built-in,
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:class:`inverted() <bidict.inverted>` should feel familiar.
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Pass in a mapping to get the inverse mapping::
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>>> from bidict import inverted
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>>> it = inverted({1: 'one'})
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>>> {k: v for (k, v) in it}
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{'one': 1}
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an iterable of pairs to get the pairs' inverses::
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>>> list(inverted([(1, 'one'), (2, 'two')]))
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[('one', 1), ('two', 2)]
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>>> list(inverted((i*i, i) for i in range(2, 5)))
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[(2, 4), (3, 9), (4, 16)]
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or any object implementing an ``__inverted__`` method,
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which objects that already know their own inverses (such as bidicts)
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can implement themselves::
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>>> from bidict import bidict
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>>> dict(inverted(bidict({1: 'one'})))
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{'one': 1}
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