==========
Why Python
==========
----------------------------
*Because XKCD said so*
----------------------------

.. class:: right

    `Morgan Goose http://morgangoose.com`
    
    October 2010
    
.. class:: handout

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    Attribution-Noncommercial-Share Alike 3.0 United States License. To
    view a copy of this license, visit
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Three simple reasons
====================

If you need to have a reason to use Python_ over some other language that you
have at your disposal, I can think of at least 3 general reasons:

    * Puts the source reader first, and has a Zen code.
    * Great built-ins and defaults
    * Documentation. It's built into the language, and leveraged everywhere
    * Ecosystem
    * Everything you can do, I can do better (mostly)

.. _Python: http://docs.python.org

Some reasons not to use Python_
===============================

While I'm liable to say and believe that this language is perfect, it's not.
That's just how things are, but here are some blemishes:

    * Threading (for non io bound)
    * Resource usage
    * A need for Pure Functional mechanisms


Why reading code is more important
==================================

*You read more than you write* 

So having a style guide for a language, that is the gold standard, means code
is code is code, and everyone starts off on the same page.

There is even a few handy checking tools like pep8 or pylint to see how well
your code stacks up to the style guide. (similar to the anal retentiveness
needed for a w3c validation badge)


Having your lists, and munging them too
=======================================

Python out of the box has and extensively leverages their small set of basic
types: list, tuple, set, dict, string, float, int, bool, etc_

.. _etc: http://docs.python.org/library/stdtypes.html

Having these types built into the language, makes them ubiquitous, and
powerful. No more making your own, or relying on third part libs to get a
decent string. Everything is well defined, and has useful mechanisms attached to
them.


Documentation before all
========================

Python docstrings are a great example of a language leveraging it's design to
promote developers to document their code, and allow for users of software to
simply access said documentation. (sometimes in manpage-esque fashion)

.. code-block:: python

    """
    Module doc
    """
    def bar():
        """ 
        Function doc
        """
        pass


We're all devs here, and we're all lazy
=======================================

So we make good tools, and share them, to make more good tools:

    * Fabric_ - ssh wrapped in great python functions
    * nose_ - extensible unit test suite
    * Sphinx_ - rst based documentation generator (docs.python.org)
    * pip_ - python package manager (think cpan/gem)
    * virtualenv_ - path monger to make simple chroot like envs
    * Mercurial_ - pure c/python dvcs
    * bpython_ - best atm python cli interpreter/tool
    * bottle_/flask_ - two similar micro web frameworks
    * sqlalchemy_/elixir_ - makes database backends decoupled.

.. _Fabric: http://docs.fabfile.org
.. _nose: http://somethingaboutorange.com/mrl/projects/nose/0.11.2/
.. _Sphinx: http://sphinx.pocoo.org/
.. _pip: http://pypi.python.org/pypi/pip
.. _virtualenv: http://pypi.python.org/pypi/virtualenv
.. _Mercurial: http://mercurial.selenic.com/
.. _bpython: http://bpython-interpreter.org/
.. _bottle: http://bottle.paws.de/docs/dev/index.html
.. _flask: http://flask.pocoo.org/
.. _sqlalchemy: http://www.sqlalchemy.org/
.. _elixir: http://elixir.ematia.de/trac/wiki


It's like a language concentrate
================================

Python is dense. You can leverage a lot of awesome things in relatively few
lines, without managing to become obfuscated:

.. code-block:: python

    >> a, b = b, a #swap a and b
    >> c, d, e = range(10) # c,d == 0,1 and e == range(10)[2:]
    >> ["%04d" %x for x in range(5)]
    ['0000', '0001', '0002', '0003', '0004']


You get to run with scissors
============================

Python will let you have a function that doesn't know what some parameters are
until run-time, as well as return multiple values:

.. code-block:: python

    def foo(a, b=None, *args, **kwargs):
        if b:
            print a, b

        for arg in args:
            print args
        for k, v in kwargs.items():
            print k, v, kwargs[k]

        return b, a, args[0]


Other fun bits being
====================

    * decorators - functions that operate on functions to modify behavior
    * generators - tool for creating iterators
    * scope with *with* - allows for with open("file.txt") as f:
    * dict comprehensions - make dictionaries on the fly
    * lambdas - anonymous functions
    * user defined exceptions - make your own errors