Metadata-Version: 2.1
Name: prime-sieve
Version: 0.1.8
Summary: An understandable prime sieve implementation in numpy or pure python.
Home-page: https://github.com/mCodingLLC/prime_sieve
Author: James Murphy
Author-email: james@mcoding.io
License: MIT license
Keywords: prime_sieve
Platform: UNKNOWN
Classifier: Development Status :: 2 - Pre-Alpha
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: MIT License
Classifier: Natural Language :: English
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.6
Classifier: Programming Language :: Python :: 3.7
Classifier: Programming Language :: Python :: 3.8
Classifier: Programming Language :: Python :: 3.9
Requires-Python: >=3.6
Requires-Dist: numpy

===========
Prime Sieve
===========


.. image:: https://img.shields.io/pypi/v/prime_sieve.svg
        :target: https://pypi.python.org/pypi/prime_sieve

.. image:: https://travis-ci.com/mCodingLLC/prime_sieve.svg?branch=master
    :target: https://travis-ci.com/mCodingLLC/prime_sieve

.. image:: https://readthedocs.org/projects/prime-sieve/badge/?version=latest
        :target: https://prime-sieve.readthedocs.io/en/latest/?badge=latest
        :alt: Documentation Status




An understandable prime sieve implementation in numpy or pure python.
The focus is providing a sieve that is easy to understand rather than the absolute fastest implementation.
Though the numpy implementation is reasonably quick,
being able to compute the first 100 million primes in 30 seconds on my mid-tier laptop.

This library implements a version of the
`segmented sieve of Eratosthenes <https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes#Segmented_sieve>`_.

First take a look at the pure python implementation in `<prime_sieve/list.py>`_.
Then see the numpy implementation in `<prime_sieve/array.py>`_.
Sieve operations that are independent of the actual computation of primes,
such as looking up the nth-prime number,
are found in `<prime_sieve/base.py>`_.


* Free software: MIT license
* Documentation: https://prime-sieve.readthedocs.io.

Usage
-----

.. code-block:: python3

    # Use a numpy or pure python implementation
    from prime_sieve.array import PrimeArraySieve
    # from prime_sieve.list import PrimeListSieve

    sieve = PrimeArraySieve()
    # sieve = PrimeListSieve()

    print(sieve.nth_prime(0)) # 2
    print(sieve[4]) # 7

    print(sieve[:100]) # [2, 3, ..., 541]
    print(sieve[1:6]) # [3, 5, 7, 11, 13]

    print(86*97 in sieve) # False
    print(sieve.is_prime(2 ** 13 - 1)) # True

    # ranges are like python ranges, inclusive start, exclusive stop
    print(sieve.primes_in_range(10, 20)) # [11, 13, 17, 19]
    print(sieve.primes_in_range(10, 19)) # [11, 13, 17]

    print(sieve.count_primes_in_range(3, 7)) # 2
    print(sieve.count_primes_in_range(3, 8)) # 3

    print(sieve.next_prime_greater_than(100)) # 101
    print(sieve.next_prime_greater_than(101)) # 103

    print(sieve.prev_prime_less_than(8)) # 7
    print(sieve.prev_prime_less_than(7)) # 5

    print(sieve.count_primes_less_or_equal(10 ** 7)) # 664579

    for p in sieve.iter_all_primes(): # infinite loop
        print(p)

    # see sieve internals
    print(len(sieve)) # how many primes have currently been computed
    print(sieve.primes) # read-only view of already computed primes


Credits
-------

This package was created with Cookiecutter_ and the `audreyr/cookiecutter-pypackage`_ project template.

.. _Cookiecutter: https://github.com/audreyr/cookiecutter
.. _`audreyr/cookiecutter-pypackage`: https://github.com/audreyr/cookiecutter-pypackage


=======
History
=======

0.1.0 (2021-05-02)
------------------

* First release on PyPI.


