https://github.com/roman-neuhauser/py-impala

Import packages and modules from arbitrary directories and files
https://github.com/roman-neuhauser/py-impala

Last synced: 13 days ago
JSON representation

Import packages and modules from arbitrary directories and files

• Host: GitHub
• URL: https://github.com/roman-neuhauser/py-impala
• Owner: roman-neuhauser
• License: mit
• Archived: true
• Created: 2013-10-09T12:14:29.000Z (about 11 years ago)
• Default Branch: master
• Last Pushed: 2014-10-15T14:17:06.000Z (about 10 years ago)
• Last Synced: 2024-10-28T23:36:06.339Z (16 days ago)
• Language: Python
• Size: 219 KB
• Stars: 19
• Watchers: 2
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.rst
  • License: LICENSE

Awesome Lists containing this project

README

        
.. vim: ft=rst sts=2 sw=2 tw=70

.. default-role:: literal

.. This file is marked up using reStructuredText.

   Lines beginning with ".." are reST directives.

   "foo_" or "`foo bar`_" is a link, defined at ".. _foo" or

   ".. _foo bar".

   "::" introduces a literal block (usually some form of code).

   "`foo`" is some kind of identifier.

   Suspicious backslashes in the text ("`std::string`\s") are required

   for reST to recognize the preceding character as syntax.

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

                              py-impala

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

----------------------------------------------------------------------

   Import packages and modules from arbitrary directories and files

----------------------------------------------------------------------

:Author: Roman Neuhauser

:Contact: [email protected]

:Copyright: This document is in the public domain.

Overview

========

Impala is a PEP302_ protocol (`sys.meta_path` hook for the `import`

statement) implementation allowing the user to import packages and

modules from arbitrarily named directories and files.

.. _PEP302: http://www.python.org/dev/peps/pep-0302/

Motivation

==========

* Comfort and freedom in development

* Installed interface available without installation

Let's say I'm developing a Python package called `pyoneer`.  I want to

lay the source code out like this: ::

  README.txt

  src/

    __init__.py

    some.py

    more.py

  tests/

    ...

The question then is, how do I `import pyoneer` in the test files

(`/tests/...`) and have it load `/src/__init__.py`?

The default `import` mechanism requires packages to live in eponymous

directories.

What's the fuss about, you ask?  I should simply rename the `src`

directory to `pyoneer` or maybe `src/pyoneer`, no?

Indeed, this would be tolerable, at least with top-level packages.

However, if I'm working on something that will be available as

`foo.bar.baz` after installation, I certainly don't want to wade

through the desolate `src/foo/bar` to get to the source code.

Maybe I could `import src` in the tests instead?  Well, tests are

a form of documentation, and doubly so with `doctest`_.  "Proper"

documentation (README.txt, etc) can also contain snippets which

should be verifiable without the CUT being installed.

*Impala* to the rescue!

::

  from os.path import abspath, dirname

  import impala

  root = abspath(dirname(__file__))

  impala.register(dict(

    pyoneer = '%s/src' % root

  ))

  import pyoneer

.. _doctest: http://docs.python.org/2/library/doctest.html

Description

===========

`impala.register(aliases)`

++++++++++++++++++++++++++

`aliases` is a `dict` mapping from fully-qualified module/package

names to paths to load from.  To import a package `p` from path

`/a/b/c`, `aliases` must include the key `p` with associated value

`/a/b/c`, and `/a/b/c/__init__.py` must be a valid package entry

point.  To import a module `m` from path `/f/g/h.py`, `aliases` must

include the key `m` with associated value `/f/g/h.py`.

Example: ::

  from os.path import abspath, dirname

  import impala

  r = dirname(abspath(__file__))

  impala.register({

    'p': '%s/a/b/c' % r,

    'p.q': '%s/f/g/h' % r,

    'p.q.m': '%s/k.py' % r,

  })

  import p

  import p.q

  import p.q.m

License

=======

*py-impala* is distributed under the `MIT license`_.  See `LICENSE`

for details.

.. _MIT license: http://opensource.org/licenses/MIT

Installation

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

Using `pip` from PyPI_, the Python Package Index: ::

  pip install impala

From a checkout_ or extracted tarball: ::

  python setup.py install

.. _PyPI:     http://pypi.python.org/pypi

.. _checkout: https://github.com/roman-neuhauser/py-impala.git

Development

===========

Source code and issue tracker are at Github:

  https://github.com/roman-neuhauser/py-impala