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from hansel import Crumb to find your file path.

Project Description
hansel
======

Flexible parametric file paths to make queries, build folder trees and smart
folder structure access.

|PyPI| |Build Status| |Coverage Status| |PyPI Downloads| |Code Health| |Scrutinizer|

Usage
=====

Quick Intro
-----------

Imagine this folder tree:

::

data
└── raw
├── 0040000
│   └── session_1
│   ├── anat_1
│   └── rest_1
├── 0040001
│   └── session_1
│   ├── anat_1
│   └── rest_1
├── 0040002
│   └── session_1
│   ├── anat_1
│   └── rest_1
├── 0040003
│   └── session_1
│   ├── anat_1
│   └── rest_1
├── 0040004
│   └── session_1
│   ├── anat_1
│   └── rest_1


.. code:: python

from hansel import Crumb

# create the crumb
crumb = Crumb("{base_dir}/data/raw/{subject_id}/{session_id}/{image_type}/{image}")

# set the base_dir path
crumb = crumb.replace('base_dir', '/home/hansel')

assert str(crumb) == "/home/hansel/data/raw/{subject_id}/{session_id}/{image_type}"

# get the ids of the subjects
subj_ids = crumb['subject_id']

assert subj_ids == ['0040000', '0040001', '0040002', '0040003', '0040004', ....]

# get the paths to the subject folders, the output can be strings or crumbs, you choose with the make_crumbs boolean argument
subj_paths = crumb.ls('subject_id', make_crumbs=True)

# set the image_type
anat_crumb = crumb.replace(image_type='anat_1')

# get the paths to the anat_1 folders
anat_paths = anat_crumb.ls('image')


Long Intro
----------

I often find myself in a work related with structured folder paths, such as the
one shown above.

I have tried many ways of solving these situations: loops, dictionaries,
configuration files, etc. I always end up doing a different thing for the same
problem over and over again.

This week I grew tired of it and decided to make a representation of a
structured folder tree in a string and access it the most easy way.

If you look at the folder structure above I have:

- the root directory from where it is hanging: ``...data/raw``,
- many identifiers (in this case a subject identification), e.g.,
``0040000``,
- session identification, ``session_1`` and
- a data type (in this case an image type), ``anat_1`` and ``rest_1``.

With ``hansel`` I can represent this folder structure like this:

.. code:: python

from hansel import Crumb

crumb = Crumb("{base_dir}/data/raw/{subject_id}/{session_id}/{image_type}")


Let's say we have the structure above hanging from a base directory like ``/home/hansel/``.

I can use the ``replace`` function to make set the ``base_dir``
parameter:

.. code:: python

crumb = crumb.replace('base_dir', '/home/hansel')

assert str(crumb) == "/home/hansel/data/raw/{subject_id}/{session_id}/{image_type}"

if you don't need a copy of ``crumb``, you can use the ``[]`` operator:

.. code:: python

crumb['base_dir'] = '/home/hansel'


Now that the root path of my dataset is set, I can start querying my
crumb path.

If I want to know the path to the existing ``subject_ids`` folders:

.. code:: python

subject_paths = anat_crumb.ls('subject_id')

The output of ``ls`` can be ``str`` or ``Crumb`` or ``pathlib.Path``.
They will be ``Path`` if there are no crumb arguments left in the crumb path.
You can choose this using the ``make_crumbs`` argument:

.. code:: python

subject_paths = anat_crumb.ls('subject_id', make_crumbs=True)

If I want to know what are the existing ``subject_ids``:

.. code:: python

subject_ids = crumb.ls('subject_id', fullpath=False)

or

.. code:: python

subject_ids = crumb['subject_id']

Now, if I wanted to get the path to all the ``anat_1`` images, I could
do this:

.. code:: python

anat_crumb = crumb.replace(image_type='anat_1')

anat_paths = anat_crumb.ls('image')

or

.. code:: python

crumb['image_type'] = 'anat_1'

anat_paths = crumb.ls('image')


More features
-------------

There are more possibilities such as:

- creating folder trees with a value of maps for the crumbs:

.. code:: python

from hansel import mktree, ParameterGrid

crumb = Crumb("/home/hansel/raw/{subject_id}/{session_id}/{modality}/{image}")

values_map = {'session_id': ['session_' + str(i) for i in range(2)],
'subject_id': ['subj_' + str(i) for i in range(3)]}

mktree(crumb, list(ParameterGrid(values_map)))


- check the feasibility of a crumb path:

.. code:: python

crumb = Crumb("/home/hansel/raw/{subject_id}/{session_id}/{modality}/{image}")

# ask if there is any subject with the image 'lollipop.png'.
crumb['image'] = 'lollipop.png'
assert crumb.exists()


- check which subjects have 'jujube.png' and 'toffee.png' files:

.. code:: python

crumb = Crumb("/home/hansel/raw/{subject_id}/{session_id}/{modality}/{image}")

toffee_crumb = crumb.replace(image='toffee.png')
jujube_crumb = crumb.replace(image='jujube.png')

# using sets functionality
set(toffee_crumb['subject_id']).intersection(set(jujube_crumb['subject_id']))


- unfold the whole crumb path to get the whole filetree in a list of paths:

.. code:: python

crumb = Crumb("/home/hansel/raw/{subject_id}/{session_id}/{modality}/{image}")
crumbs = crumb.unfold()

# and you can ask for the value of the crumb argument in each element
crumbs[0]['subject_id']


More functionalities, ideas and comments are welcome.


Dependencies
============

Please see the requirements.txt file. Before installing this package,
install its dependencies with:

pip install -r requirements.txt


Install
=======

I am only testing this tool on Python 3.4 and 3.5.
Maybe it works on Python 2.7 too, having `six` and `pathlib2` installed.

This package uses setuptools. You can install it running:

python setup.py install

If you already have the dependencies listed in requirements.txt
installed, to install in your home directory, use:

python setup.py install --user

To install for all users on Unix/Linux:

| python setup.py build
| sudo python setup.py install

You can also install it in development mode with:

python setup.py develop


Development
===========

Code
----

Github
~~~~~~

You can check the latest sources with the command:

git clone https://www.github.com/alexsavio/hansel.git

or if you have write privileges:

git clone git@github.com:alexsavio/hansel.git

If you are going to create patches for this project, create a branch
for it from the master branch.

We tag stable releases in the repository with the version number.

Testing
-------

We are using `py.test <http://pytest.org/>`__ to help us with the testing.

Otherwise you can run the tests executing:

python setup.py test

or

py.test


.. |PyPI| image:: https://img.shields.io/pypi/v/hansel.svg
:target: https://pypi.python.org/pypi/hansel

.. |Build Status| image:: https://travis-ci.org/alexsavio/hansel.svg?branch=master
:target: https://travis-ci.org/alexsavio/hansel

.. |Coverage Status| image:: https://coveralls.io/repos/alexsavio/hansel/badge.svg?branch=master&service=github
:target: https://coveralls.io/github/alexsavio/hansel?branch=master

.. |PyPI Downloads| image:: https://img.shields.io/pypi/dm/hansel.svg
:target: https://pypi.python.org/pypi/hansel

.. |Code Health| image:: https://landscape.io/github/alexsavio/hansel/master/landscape.svg?style=flat
:target: https://landscape.io/github/alexsavio/hansel/master
:alt: Code Health

.. |Scrutinizer| image:: https://img.shields.io/scrutinizer/g/alexsavio/hansel.svg
:target: https://scrutinizer-ci.com/g/alexsavio/hansel/?branch=master
:alt: Scrutinizer Code Quality

=========
Changelog
=========


Version 0.4.0
==============

- Fill CHANGES.rst
- All outputs from `Crumb.ls` function will be sorted.
- Add regular expressions or `fnmatch` option for crumb arguments.
- Change `exists` behaviour. Now the empty crumb arguments will return False when `exist()`.
- Code clean up.
- Fix bugs


Version 0.3.1
==============

- Fix README
- Code clean up.


Version 0.3.0
==============

- Add `_argval` member, a dict which stores crumb arguments replacements.
- Add tests.
- Remove `rm_dups` option in `Crumb.ls` function.
- Remove conversion to `Paths` when `Crumb` has no crumb arguments in `Crumb.ls`.


Version 0.2.0
==============

- Add `ignore_list` parameter in `Crumb` constructor.


Version 0.1.1
==============

- Add `Crumb.unfold` function.
- Move `mktree` out of `Crumb` class.


Version 0.1.0
==============

- Simplify code.
- Increase test coverage.
- Add `exist_check` to `Crumb.ls` function.
- Fix bugs.
Release History

Release History

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