Monk
~~~~

An unobtrusive data modeling, manipulation and validation library.

Supports MongoDB out of the box. Can be used for any other DB (or even without one).

Installation
------------

    $  pip install monk

Dependencies
------------

`Monk` is tested against the following versions of Python:

* CPython 2.6, 2.7, 3.2, 3.3
* PyPy 2.0

The MongoDB extension requires `pymongo`.

Documentation
-------------

See the `complete documentation`_ for details. 

.. _complete documentation: http://packages.python.org/monk

Examples
--------

Modeling
........

The schema is defined as a template using native Python data types::

    # we will reuse this structure in examples below

    spec = {
        'title': 'Untitled',
        'comments': [
            { 'author': str,
              'date': datetime.datetime.utcnow,
              'text': str
            }
        ],
    }

You are free to design as complex a document as you need.
The `manipulation` and `validation` functions (described below) support
arbitrary nested structures.

Manipulation
............

The schema can be used to create full documents from incomplete data:

.. code-block:: python

    from monk.manipulation import merged

    # default values are set for missing keys

    >>> merged(spec, {})
    { 'title': 'Untitled',
      'comments': []
    }

    # it's easy to override the defaults

    >>> merged(spec, {'title': 'Hello'})
    { 'title': 'Hello',
      'comments': []
    }

    # nested lists of dictionaries can be auto-filled, too.
    # by the way, note the date.

    >>> merged(spec, {'comments': ['author': 'john']})
    { 'title': 'Untitled',
      'comments': [
            { 'author': 'john',
              'date': datetime.datetime(2013, 3, 3, 1, 8, 4, 152113),
              'text': None
            }
        ]
    }

Validation
..........

The same schema can be used to ensure that the document has correct structure
and the values are of correct types:

.. code-block:: python

    from monk.validation import validate

    # correct data: staying silent

    >>> validate(spec, data)

    # a key is missing

    >>> validate(spec, {'title': 'Hello'})
    Traceback (most recent call last):
       ...
    monk.errors.MissingKey: comments

    # a key is missing in a dictionary in a nested list

    >>> validate(spec, {'comments': [{'author': 'john'}]}
    Traceback (most recent call last):
       ...
    monk.errors.MissingKey: comments: #0: date

    # type check; also works with functions and methods (by return value)

    >>> validation.validate(spec, {'title': 123, 'comments': []})
    Traceback (most recent call last):
        ...
    TypeError: title: expected str, got int 123

Custom validators can be used.  Behaviour can be fine-tuned.

The library can be also viewed as a framework for building ODMs
(object-document mappers).  See the MongoDB extension and note how it reuses
mixins provided by DB-agnostic modules.

Here's an example of the MongoDB ODM bundled with Monk::

    from monk.mongo import Document

    class Item(Document):
        structure = dict(text=unicode, slug=unicode)
        indexes = dict(text=None, slug=dict(unique=True))

    # this involves manipulation (inserting missing fields)
    item = Item(text=u'foo', slug=u'bar')

    # this involves validation
    item.save(db)

Links
-----

* `Project home page`_ (Bitbucket)
* `Documentation`_ (Read the Docs)
* `Package distribution`_ (PyPI)
* Questions, requests, bug reports, etc.:

  * `Issue tracker`_
  * Direct e-mail (neithere at gmail com)

.. _project home page: http://bitbucket.org/neithere/monk/
.. _documentation: http://monk.readthedocs.org
.. _package distribution: http://pypi.python.org/pypi/monk
.. _issue tracker: http://bitbucket.org/neithere/monk/issues/

Author
------

Originally written by Andrey Mikhaylenko since 2011.

Please feel free to submit patches, report bugs or request features:

    http://bitbucket.org/neithere/monk/issues/

Licensing
---------

Monk is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published
by the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

Monk is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License
along with Monk.  If not, see <http://gnu.org/licenses/>.
