https://github.com/jwodder/permutation

Permutations of finitely many positive integers
https://github.com/jwodder/permutation

available-on-pypi group-theory math mathematics maths permutation python symmetric-group

Last synced: 24 days ago
JSON representation

Permutations of finitely many positive integers

• Host: GitHub
• URL: https://github.com/jwodder/permutation
• Owner: jwodder
• License: mit
• Created: 2017-09-02T20:22:24.000Z (over 7 years ago)
• Default Branch: master
• Last Pushed: 2024-12-01T12:58:42.000Z (about 1 month ago)
• Last Synced: 2024-12-09T18:11:44.748Z (about 1 month ago)
• Topics: available-on-pypi, group-theory, math, mathematics, maths, permutation, python, symmetric-group
• Language: Python
• Size: 139 KB
• Stars: 16
• Watchers: 3
• Forks: 5
• Open Issues: 13
• Metadata Files:
  • Readme: README.rst
  • Changelog: CHANGELOG.md
  • License: LICENSE

Awesome Lists containing this project

README

        
|repostatus| |ci-status| |coverage| |pyversions| |license|

.. |repostatus| image:: https://www.repostatus.org/badges/latest/active.svg

    :target: https://www.repostatus.org/#active

    :alt: Project Status: Active — The project has reached a stable, usable

          state and is being actively developed.

.. |ci-status| image:: https://github.com/jwodder/permutation/actions/workflows/test.yml/badge.svg

    :target: https://github.com/jwodder/permutation/actions/workflows/test.yml

    :alt: CI Status

.. |coverage| image:: https://codecov.io/gh/jwodder/permutation/branch/master/graph/badge.svg

    :target: https://codecov.io/gh/jwodder/permutation

.. |pyversions| image:: https://img.shields.io/pypi/pyversions/permutation.svg

    :target: https://pypi.org/project/permutation

.. |license| image:: https://img.shields.io/github/license/jwodder/permutation.svg

    :target: https://opensource.org/licenses/MIT

    :alt: MIT License

`GitHub `_

| `PyPI `_

| `Documentation `_

| `Issues `_

| `Changelog `_

``permutation`` provides a ``Permutation`` class for representing `permutations

`_ of finitely many positive

integers in Python.  Supported operations & properties include inverses, (group

theoretic) order, parity, composition/multiplication, cycle decomposition,

cycle notation, word representation, Lehmer codes, and, of course, use as a

callable on integers.

Installation

============

``permutation`` requires Python 3.8 or higher.  Just use `pip

`_ for Python 3 (You have pip, right?) to install::

    python3 -m pip install permutation

Examples

========

>>> from permutation import Permutation

>>> p = Permutation(2, 1, 4, 5, 3)

>>> p(1)

2

>>> p(3)

4

>>> p(42)

42

>>> p.to_cycles()

[(1, 2), (3, 4, 5)]

>>> print(p)

(1 2)(3 4 5)

>>> print(p.inverse())

(1 2)(3 5 4)

>>> p.degree

5

>>> p.order

6

>>> p.is_even

False

>>> p.lehmer(5)

27

>>> q = Permutation.cycle(1,2,3)

>>> print(p * q)

(2 4 5 3)

>>> print(q * p)

(1 3 4 5)

>>> for p in Permutation.group(3):

...     print(p)

...

1

(1 2)

(2 3)

(1 3 2)

(1 2 3)

(1 3)