aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/python/pygtrie/py3/.dist-info/METADATA
blob: bb995593365f59297bd45f317a89d8b40eb3466f (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
Metadata-Version: 2.1
Name: pygtrie
Version: 2.5.0
Summary: A pure Python trie data structure implementation.
Home-page: https://github.com/mina86/pygtrie
Author: Michal Nazarewicz
Author-email: mina86@mina86.com
License: Apache-2.0
Download-URL: https://github.com/mina86/pygtrie/tarball/v2.5.0
Keywords: trie,prefix tree,data structure
Platform: Platform Independent
Classifier: Development Status :: 5 - Production/Stable
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: Apache Software License
Classifier: Operating System :: OS Independent
Classifier: Programming Language :: Python
Classifier: Programming Language :: Python :: 2
Classifier: Programming Language :: Python :: 2.7
Classifier: Programming Language :: Python :: 3
Classifier: Topic :: Software Development :: Libraries :: Python Modules
License-File: LICENSE

pygtrie
=======

pygtrie is a pure Python implementation of a trie data structure
compatible with Python 2.x and Python 3.x.

`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, simply run::

    pip install pygtrie

or by adding line such as::

    pygtrie == 2.*

to project’s `requirements file
<https://pip.pypa.io/en/latest/user_guide/#requirements-files>`_.
Alternatively, if installation from source is desired, it can be
achieved by executing::

    python setup.py install

Version History
---------------

2.5: 2022/07/16

- Add ``pygtrie.Trie.merge`` method which merges structures of two
  tries.

- Add ``pygtrie.Trie.strictly_equals`` method which compares two
  tries with stricter rules than regular equality operator.  It’s not
  sufficient that keys and values are the same but the structure of
  the tries must be the same as well.  For example:

      >>> t0 = StringTrie({'foo/bar.baz': 42}, separator='/')
      >>> t1 = StringTrie({'foo/bar.baz': 42}, separator='.')
      >>> t0 == t1
      True
      >>> t0.strictly_equals(t1)
      False

- Fix ``pygtrie.Trie.__eq__`` implementation such that key values
  are taken into consideration rather than just looking at trie
  structure.  To see what this means it’s best to look at a few
  examples.  Firstly:

      >>> t0 = StringTrie({'foo/bar': 42}, separator='/')
      >>> t1 = StringTrie({'foo.bar': 42}, separator='.')
      >>> t0 == t1
      False

  This used to be true since the two tries have the same node
  structure.  However, as far as Mapping interface is concerned, they
  use different keys, i.e. ```set(t0) != set(t1)``.  Secondly:

      >>> t0 = StringTrie({'foo/bar.baz': 42}, separator='/')
      >>> t1 = StringTrie({'foo/bar.baz': 42}, separator='.')
      >>> t0 == t1
      True

  This used to be false since the two tries have different node
  structures (the first one splits key into ``('foo', 'bar.baz')``
  while the second into ``('foo/bar', 'baz')``).  However, their keys
  are the same, i.e. ```set(t0) == set(t1)``.  And lastly:

      >>> t0 = Trie({'foo': 42})
      >>> t1 = CharTrie({'foo': 42})
      >>> t0 == t1
      False

  This used to be true since the two tries have the same node
  structure.  However, the two classes return key as different values.
  ``pygtrie.Trie`` returns keys as tuples while
  ``pygtrie.CharTrie`` returns them as strings.

2.4.2: 2021/01/03

- Remove use of ‘super’ in ``setup.py`` to fix compatibility with
  Python 2.7.  This changes build code only; no changes to the library
  itself.

2.4.1: 2020/11/20

- Remove dependency on ``packaging`` module from ``setup.py`` to fix
  installation on systems without that package.  This changes build
  code only; no changes to the library itself.  [Thanks to Eric
  McLachlan for reporting]

2.4.0: 2020/11/19  [pulled back from PyPi]

- Change ``children`` argument of the ``node_factory`` passed to
  ``pygtrie.Trie.traverse`` from a generator to an iterator with
  a custom bool conversion.  This allows checking whether node has
  children without having to iterate over them (``bool(children)``)

  To test whether this feature is available, one can check whether
  `Trie.traverse.uses_bool_convertible_children` property is true,
  e.g.: ``getattr(pygtrie.Trie.traverse,
  'uses_bool_convertible_children', False)``.

  [Thanks to Pallab Pain for suggesting the feature]

2.3.3: 2020/04/04

- Fix to ‘``AttributeError``: ``_NoChildren`` object has no
  attribute ``sorted_items``’ failure when iterating over a trie with
  sorting enabled.  [Thanks to Pallab Pain for reporting]

- Add ``value`` property setter to step objects returned by
  ``pygtrie.Trie.walk_towards`` et al.  This deprecates the
  ``set`` method.

- The module now exports `pygtrie.__version__` making it possible to
  determine version of the library at run-time.

2.3.2: 2019/07/18

- Trivial metadata fix

2.3.1: 2019/07/18  [pulled back from PyPi]

- Fix to ``pygtrie.PrefixSet`` initialisation incorrectly storing
  elements even if their prefixes are also added to the set.

  For example, ``PrefixSet(('foo', 'foobar'))`` incorrectly resulted
  in a two-element set even though the interface dictates that only
  ``foo`` is kept (recall that if ``foo`` is member of the set,
  ``foobar`` is as well).  [Thanks to Tal Maimon for reporting]

- Fix to ``pygtrie.Trie.copy`` method not preserving
  enable-sorting flag and, in case of ``pygtrie.StringTrie``,
  ``separator`` property.

- Add support for the ``copy`` module so ``copy.copy`` can now be
  used with trie objects.

- Leafs and nodes with just one child use more memory-optimised
  representation which reduces overall memory usage of a trie
  structure.

- Minor performance improvement for adding new elements to
  a ``pygtrie.PrefixSet``.

- Improvements to string representation of objects which now includes
  type and, for ``pygtrie.StringTrie`` object, value of separator
  property.

2.3: 2018/08/10

- New ``pygtrie.Trie.walk_towards`` method allows walking a path
  towards a node with given key accessing each step of the path.
  Compared to `pygtrie.Trie.walk_prefixes` method, steps for nodes
  without assigned values are returned.

- Fix to ``pygtrie.PrefixSet.copy`` not preserving type of backing
  trie.

- ``pygtrie.StringTrie`` now checks and explicitly rejects empty
  separators.  Previously empty separator would be accepted but lead
  to confusing errors later on.  [Thanks to Waren Long]

- Various documentation improvements, Python 2/3 compatibility and
  test coverage (python-coverage reports 100%).