exceptbool 1.2.1
Converts caught exception into bool value.
License: MIT license
Keywords: except exception catching bool boolean decorator context manager

==========
exceptbool
==========

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

.. image:: https://pepy.tech/badge/exceptbool
        :target: https://pepy.tech/badge/exceptbool

.. image:: https://travis-ci.org/konrad-kocik/exceptbool.svg?branch=master
        :target: https://travis-ci.org/konrad-kocik/exceptbool.svg?branch=master

.. image:: https://readthedocs.org/projects/exceptbool/badge/?version=latest
        :target: https://exceptbool.readthedocs.io/en/latest/?badge=latest

Converts caught exception into bool value.

* Free software: `MIT license`_
* Documentation: https://exceptbool.readthedocs.io.
* Issue reporting: https://github.com/konrad-kocik/exceptbool/issues/new

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

Features
--------

How many of those have you written in your life?

.. code-block:: python

    def is_something_possible():
        try:
            do_something()
            return True
        except DoingSomethingError:
            return False

Ugh! A perfect example of six-line boilerplate code. With exceptbool you can shorten that into only three lines!

.. code-block:: python

    @except_to_bool(exc=DoingSomethingError)
    def is_something_possible():
        do_something()

Exceptbool makes decorated function return bool instead of raising an exception by converting given exception(s) into given bool value. If no exception will be raised, then negation of given bool will be returned. If exception different than given one will be raised, then it will not be caught.

Don't want to decorate whole function? Fine, you can convert exception raised from chosen block of code by using context manager:

.. code-block:: python

    with except_converter(exc=DoingSomethingError) as converted_exception:
        do_something()

============
Installation
============

Stable release
--------------

To install exceptbool, run this command in your terminal:

.. code-block:: console

    $ pip install exceptbool

This is the preferred method to install exceptbool, 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.

.. _pip: https://pip.pypa.io
.. _Python installation guide: http://docs.python-guide.org/en/latest/starting/installation/

From sources
------------

The sources for exceptbool can be downloaded from the `Github repo`_.

You can either clone the public repository:

.. code-block:: console

    $ git clone https://github.com/konrad-kocik/exceptbool.git

Or download the `tarball`_:

.. code-block:: console

    $ curl  -OL https://github.com/konrad-kocik/exceptbool/tarball/master

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

.. code-block:: console

    $ python setup.py install


.. _Github repo: https://github.com/konrad-kocik/exceptbool
.. _tarball: https://github.com/konrad-kocik/exceptbool/tarball/master

=====
Usage
=====

As decorator
------------

First, import ``except_to_bool`` decorator into current namespace:

.. code-block:: python

     from exceptbool import except_to_bool

To catch any exception and convert it into False:

.. code-block:: python

    @except_to_bool
    def decorated_function():
        error_raising_function()

Now ``decorated_function`` will return False if ``error_raising_function`` raises Exception, True otherwise.

To catch given exception and convert it into given bool value:

.. code-block:: python

    @except_to_bool(exc=ValueError, to=True)
    def decorated_function():
       error_raising_function()

Now ``decorated_function`` will return True if ``error_raising_function`` raises ValueError, False otherwise.

To catch any of multiple exceptions:

.. code-block:: python

    @except_to_bool(exc=(TypeError, TimeoutError))
    def decorated_function():
       error_raising_function()

Now ``decorated_function`` will return False if ``error_raising_function`` raises TypeError or TimeoutError, True otherwise.

Function decorated with ``except_to_bool`` is perfectly capable of accepting positional and keyword arguments:

.. code-block:: python

    @except_to_bool
    def decorated_function(*args, **kwargs):
        error_raising_function(*args, **kwargs)

    decorated_function("foo", bar="baz")  # no error

As context manager
------------------

First, import ``except_converter`` context manager into current namespace:

.. code-block:: python

     from exceptbool import except_converter

To catch any exception and convert it into False:

.. code-block:: python

    with except_converter() as converted_exception:
        error_raising_function()

Now ``converted_exception.value`` will return False if ``error_raising_function`` raises Exception, True otherwise.

To catch given exception and convert it into given bool value:

.. code-block:: python

    with except_converter(exc=ValueError, to=True) as converted_exception:
       error_raising_function()

Now ``converted_exception.value`` will return True if ``error_raising_function`` raises ValueError, False otherwise.

To catch any of multiple exceptions:

.. code-block:: python

    with except_converter(exc=(OSError, KeyError)) as converted_exception:
       error_raising_function()

Now ``converted_exception.value`` will return False if ``error_raising_function`` raises OSError or KeyError, True otherwise.

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

1.2.1 (2019-01-19)
------------------

* Improved documentation.

1.2.0 (2019-01-12)
------------------

* Added possibility to convert exceptions by using context manager.

1.1.0 (2018-12-18)
------------------

* Added support for Python 3.5.

1.0.1 (2018-12-12)
------------------

* Updated and improved documentation.

1.0.0 (2018-12-10)
------------------

* First release on PyPI with basic functionality.