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pygtrie
=======
.. image:: https://readthedocs.org/projects/pygtrie/badge/?version=latest
:target: http://pygtrie.readthedocs.io/en/latest/
:alt: Documentation Status (latest)
.. image:: https://readthedocs.org/projects/pygtrie/badge/?version=stable
:target: http://pygtrie.readthedocs.io/en/stable/
:alt: Documentation Status (stable)
pygtrie is a Python library implementing a trie data structure.
`Trie data structure <http://en.wikipedia.org/wiki/Trie>`_, also known
as radix or prefix tree, is a tree associating keys to values where
all the descendants of a node have a common prefix (associated with
that node).
The trie module contains ``Trie``, ``CharTrie`` and ``StringTrie``
classes each implementing a mutable mapping interface, i.e. ``dict``
interface. As such, in most circumstances, ``Trie`` could be used as
a drop-in replacement for a ``dict``, but the prefix nature of the
data structure is trie’s real strength.
The module also contains ``PrefixSet`` class which uses a trie to
store a set of prefixes such that a key is contained in the set if it
or its prefix is stored in the set.
Features
--------
- A full mutable mapping implementation.
- Supports iterating over as well as deleting a subtrie.
- Supports prefix checking as well as shortest and longest prefix
look-up.
- Extensible for any kind of user-defined keys.
- A PrefixSet supports “all keys starting with given prefix” logic.
- Can store any value including None.
Installation
------------
To install pygtrie, run::
pip install pygtrie
Or download the sources and save ``pygtrie.py`` file with your
project.
Upgrading from 0.9.x
--------------------
The 1.0 release introduced backwards incompatibility in naming. The
module has been renamed from ``trie`` to ``pygtrie``. Fortunately,
updating scripts using pygtrie should boil down to replacing::
from pytrie import trie
with::
import pygtrie as trie
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