Welcome to yail’s documentation!

Contents:

yail

Yet Another Iterator Library for Python.

• Free software: BSD 3-Clause
• Documentation: https://yail.readthedocs.io.

Features

• TODO

Credits

This package was created with Cookiecutter and the nanshe-org/nanshe-cookiecutter project template.

Installation

Stable release

To install yail, run this command in your terminal:

$ pip install yail

This is the preferred method to install yail, as it will always install the most recent stable release.

If you don’t have pip installed, this Python installation guide can guide you through the process.

From sources

The sources for yail can be downloaded from the Github repo.

You can either clone the public repository:

$ git clone git://github.com/jakirkham/yail

Or download the tarball:

$ curl  -OL https://github.com/jakirkham/yail/tarball/master

Once you have a copy of the source, you can install it with:

$ python setup.py install

Usage

To use yail in a project:

import yail

API

yail package

Submodules

yail.core module

yail.core.cycles(seq, n=1)

Cycles through the sequence n-times.

Basically the same as itertools.cycle except that this sets an upper limit on how many cycles will be done.

Note

If n is None, this is identical to itertools.cycle.

Parameters:

• seq (iterable) – The sequence to grab items from.
• n (integral) – Number of times to cycle through.

Returns:

The cycled sequence generator.

Return type:

generator

Examples

>>> list(cycles([1, 2, 3], 2))
[1, 2, 3, 1, 2, 3]

yail.core.disperse(seq)

Similar to range except that it recursively proceeds through the given range in such a way that values that follow each other are preferably not only non-sequential, but fairly different. This does not always work with small ranges, but works nicely with large ranges.

Parameters:

• a (int) – the lower bound of the range
• b (int) – the upper bound of the range

Returns:

a generator that can be used to iterate

through the sequence.

Return type:

result(generator)

Examples

>>> list(disperse(range(10)))
[0, 5, 8, 3, 9, 4, 6, 1, 7, 2]

yail.core.duplicate(seq, n=1)

Gets each element multiple times.

Like itertools.repeat this will repeat each element n-times. However, it will do this for each element of the sequence.

Parameters:

• seq (iterable) – The sequence to grab items from.
• n (integral) – Number of repeats for each element.

Returns:

A generator of repeated elements.

Return type:

generator

Examples

>>> list(duplicate([1, 2, 3], 2))
[1, 1, 2, 2, 3, 3]

yail.core.empty()

Creates an empty iterator.

Examples

>>> list(empty())
[]

yail.core.generator(it)

Creates a generator type from the iterable.

Parameters:it (iterable) – An iterable to make a generator. Returns:A generator made from the iterable. Return type:generator

Examples

>>> generator(range(5))  # doctest: +ELLIPSIS
<generator object generator at 0x...>

>>> list(generator(range(5)))
[0, 1, 2, 3, 4]

yail.core.indices(*sizes)

Iterates over a length/shape.

Takes a size or sizes (unpacked shape) and iterates through all combinations of the indices.

Parameters:*sizes (int) – list of sizes to iterate over. Returns:an iterator over the sizes. Return type:iterable

Examples

>>> list(indices(3, 2))
[(0, 0), (0, 1), (1, 0), (1, 1), (2, 0), (2, 1)]

yail.core.pad(seq, before=0, after=0, fill=None)

Pads a sequence by a fill value before and/or after.

Pads the sequence before and after using the fill value provided by fill up to the lengths specified by before and after. If either before or after is None, pad the fill value infinitely on the respective end.

Note

If before``is ``None, the sequence will only be the fill value.

Parameters:

• seq (iterable) – Sequence to pad.
• before (integral) – Amount to pad before.
• after (integral) – Amount to pad after.
• fill (any) – Some value to pad with.

Returns:

A sequence that has been padded.

Return type:

iterable

Examples

>>> list(pad(range(2, 4), before=1, after=2, fill=0))
[0, 2, 3, 0, 0]

yail.core.single(val)

Creates an iterator with a single value.

Parameters:val (any) – Single value to add to the iterator. Returns:An iterable yielding the single value. Return type:iterable

Examples

>>> list(single(1))
[1]

yail.core.sliding_window_filled(seq, n, pad_before=False, pad_after=False, fillvalue=None)

A sliding window with optional padding on either end..

Parameters:

• seq (iter) – an iterator or something that can be turned into an iterator
• n (int) – number of generators to create as lagged
• pad_before (bool) – whether to continue zipping along the longest generator
• pad_after (bool) – whether to continue zipping along the longest generator
• fillvalue – value to use to fill generators shorter than the longest.

Returns:

a generator object that will return

values from each iterator.

Return type:

generator object

Examples

>>> list(sliding_window_filled(range(5), 2))
[(0, 1), (1, 2), (2, 3), (3, 4)]

>>> list(sliding_window_filled(range(5), 2, pad_after=True))
[(0, 1), (1, 2), (2, 3), (3, 4), (4, None)]

>>> list(sliding_window_filled(range(5), 2, pad_before=True, pad_after=True))
[(None, 0), (0, 1), (1, 2), (2, 3), (3, 4), (4, None)]

yail.core.split(n, seq)

Splits the sequence around element n.

Provides 3 ``iterable``s in return.

1. Everything before the n-th value.
2. An iterable with just the n-th value.
3. Everything after the n-th value.

Parameters:

• n (integral) – Index to split the iterable at.
• seq (iterable) – The sequence to split.

Returns:

Each portion of the iterable

around the index.

Return type:

tuple of ``iterable``s

Examples

>>> list(map(tuple, split(2, range(5))))
[(0, 1), (2,), (3, 4)]

>>> list(map(tuple, split(2, [10, 20, 30, 40, 50])))
[(10, 20), (30,), (40, 50)]

yail.core.subrange(start, stop=None, step=None, substep=None)

Generates start and stop values for each subrange.

Parameters:

• start (int) – First value in range (or last if only specified value)
• stop (int) – Last value in range
• step (int) – Step between each range
• substep (int) – Step within each range

Yields:

range – A subrange within the larger range.

Examples

>>> list(map(list, subrange(5)))
[[0], [1], [2], [3], [4]]

>>> list(map(list, subrange(0, 12, 3, 2)))
[[0, 2], [3, 5], [6, 8], [9, 11]]

Contributing

Contributions are welcome, and they are greatly appreciated! Every little bit helps, and credit will always be given.

You can contribute in many ways:

Types of Contributions

Report Bugs

Report bugs at https://github.com/jakirkham/yail/issues.

If you are reporting a bug, please include:

• Your operating system name and version.
• Any details about your local setup that might be helpful in troubleshooting.
• Detailed steps to reproduce the bug.

Fix Bugs

Look through the GitHub issues for bugs. Anything tagged with “bug” and “help wanted” is open to whoever wants to implement it.

Implement Features

Look through the GitHub issues for features. Anything tagged with “enhancement” and “help wanted” is open to whoever wants to implement it.

Write Documentation

yail could always use more documentation, whether as part of the official yail docs, in docstrings, or even on the web in blog posts, articles, and such.

Submit Feedback

The best way to send feedback is to file an issue at https://github.com/jakirkham/yail/issues.

If you are proposing a feature:

• Explain in detail how it would work.
• Keep the scope as narrow as possible, to make it easier to implement.
• Remember that this is a volunteer-driven project, and that contributions are welcome :)

Get Started!

Ready to contribute? Here’s how to set up yail for local development.

1. Fork the yail repo on GitHub.

2. Clone your fork locally:

   $ git clone git@github.com:your_name_here/yail.git
   

3. Install your local copy into an environment. Assuming you have conda installed, this is how you set up your fork for local development (on Windows drop source). Replace “<some version>” with the Python version used for testing.:

   $ conda create -n yailenv python="<some version>"
   $ source activate yailenv
   $ python setup.py develop
   

4. Create a branch for local development:

   $ git checkout -b name-of-your-bugfix-or-feature
   

   Now you can make your changes locally.

5. When you’re done making changes, check that your changes pass flake8 and the tests, including testing other Python versions:

   $ flake8 yail tests
   $ python setup.py test or py.test
   

   To get flake8, just conda install it into your environment.

6. Commit your changes and push your branch to GitHub:

   $ git add .
   $ git commit -m "Your detailed description of your changes."
   $ git push origin name-of-your-bugfix-or-feature
   

7. Submit a pull request through the GitHub website.

Pull Request Guidelines

Before you submit a pull request, check that it meets these guidelines:

1. The pull request should include tests.
2. If the pull request adds functionality, the docs should be updated. Put your new functionality into a function with a docstring, and add the feature to the list in README.rst.
3. The pull request should work for Python 2.7, 3.4 and 3.5. Check https://travis-ci.org/jakirkham/yail/pull_requests and make sure that the tests pass for all supported Python versions.

Tips

To run a subset of tests:

$ python -m unittest tests.test_yail

Indices and tables

• Index
• Module Index
• Search Page