• Source : https://github.com/jul/archery
• Tickets : https://github.com/jul/archery/issues?state=open
• Latest documentation : http://archery.readthedocs.org/en/latest/index.html

What is archery?

It is set of Mixins to use on MutableMapping giving the following features :

• Linear Algebrae;
• Vector like metrics;
• Searchable behaviour;

for convenience 3 concrete classes are provided :

• mdict (dict that follow the rules of linear algebrae based on dict);
• vdict (dict that have cos, abs, dot product);
• sdict (dict that are easily searchable);

Basic Usage

Using the ready to use class derived from dict

mdict

dict that supports consistently all the linear algebrae properties

Basically : dict that are vectors on arbitrary basis (recursively).

To learn more about its use and implementation:

• Video presentation in FOSDEM 2017
• or look at the presentation

ex:

>>> from archery import mdict
>>> point = mdict(x=1, y=1, z=1)
>>> point2 = mdict(x=1, y=-1)
>>> print( (2 * point + point2)/4)
>>> # OUT : {'y': 0.25, 'x': 0.75, 'z': 0.5}
>>> print(point - point2)
>>> # OUT : {'y': 2, 'x': 0, 'z': 1}
>>> b=mdict(x=2, z=-1)
>>> a=mdict(x=1, y=2.0)
>>> a+b
>>> # OUT: {'y': 2.0, 'x': 3, 'z': -1}
>>> b-a
>>> # OUT: {'y': -2.0, 'x': 1, 'z': -1}
>>> -(a-b)
>>> # OUT: {'y': -2.0, 'x': 1, 'z': -1}
>>> a+1
>>> # OUT: {'y': 3.0, 'x': 2}
>>> -1-a
>>> # OUT: {'y': -3.0, 'x': -2}
>>> a*b
>>> # OUT: {'x': 2}
>>> a/b
>>> # OUT: {'x': 0}
>>> 1.0*a/b
>>> # OUT: {'x': 0.5}

vdict

dict that defines abs(), dot(), cos() in the euclidean meaning

ex:

>>> from archery import vdict as Point
>>>
>>> u = Point(x=1, y=1)
>>> v = Point(x=1, y=0)
>>> u.cos(v)
>>> 0.7071067811865475
>>> u.dot(v)
>>> # OUT: 1
>>> u.cos(2*v)
>>> # OUT: 0.7071067811865475
>>> u.dot(2*v)
>>> #OUT: 2
>>> abs(u)
>>> #OUT: 1.4142135623730951
>>> u3 = Point(x=1, y=1, z=2)
>>> u4 = Point(x=1, y=3, z=4)
>>> u3 + u4
>>> #OUT: dict(x=2, y=4, z=6)
>>> assert u4 + u4 == 2*u4
>>> from archery import vdict
>>> from math import acos, pi
>>> point = vdict(x=1, y=1, z=1)
>>> point2 = vdict(x=1, y=-1)
>>> point2 = mdict(x=1, y=-1)
>>> print( (2 * point + point2)/4)
>>> # OUT : {'y': 0.25, 'x': 0.75, 'z': 0.5}
>>> print(acos(vdict(x=1,y=0).cos(vdict(x=1, y=1)))*360/2/pi)
>>> # OUT : 45.0
>>> print(abs(vdict(x=1, y=1)))
>>> # OUT : 1.41421356237
>>> print(vdict(x=1,y=0,z=3).dot(vdict(x=1, y=1, z=-1)))
>>> #OUT -2

sdict

dict made for searching value/keys/Path with special interests.

Basically, it returns an iterator in the form of a tuple being all the keys and the value. It is a neat trick, if you combine it with make_from_path, it helps select exactly what you want in a dict:

>>> from archery import sdict, make_from_path
>>> tree = sdict(
...      a = 1,
...      b = dict(
...          c = 3.0,
...          d = dict(e=True)
...      ),
...      point = dict( x=1, y=1, z=0),
... )
>>> list(tree.leaf_search(lambda x: type(x) is float ))
>>> #Out: [3.0]
>>> res = list(tree.search(lambda x: ("point") in x ))
>>> ## equivalent to list(tree.search(lambda x: Path(x).contains("point")))
>>> print(res)
>>> #Out: [('point', 'y', 1), ('point', 'x', 1), ('point', 'z', 0)]
>>> make_from_path(dict(), res)
>>> # {('point', 'y', 1): {('point', 'x', 1): ('point', 'z', 0)}}

Advanced usage

This library is a proof of the consistent use of Mixins on MutableMapping gives the property seen in the basic usage.

The Mixins do not require any specifics regarding the implementation and should work if I did my job properly with any kinds of MutableMapping.

Here is an example of a cosine similarities out of the box on the Collections.Counter :

>>> from collections import Counter
>>> from archery import VectorDict
>>> class CWCos(VectorDict, Counter):
...     pass
>>>
>>> CWCos(["mot", "wut", "wut", "bla"]).cos(CWCos(["mot","wut", "bla"]))
>>> # OUT: 0.942809041582

You can also inherit LinearAlgebrae

Resource

Ticketing: https://github.com/jul/archery/issues?state=open Source: https://github.com/jul/archery Latest documentation: http://archery.readthedocs.org/en/latest/index.html