Python features for a PHP refugee

These are things that particularly impressed me
when I decided I had had enough of [PHP][php] and I really ought to look at
[the crazy white-space language called Python][python] that was used by
[Plone][plone], [Trac][trac] and [Django][django].

The [Zen of Python][zen] states most of this in 19 lines, for all you
_tl;dr_ types.

Name-spaces and a minimal set of built-ins
——————————————

I like that the set of keywords is small, and that the built-in methods are
not much larger. This leaves you with an unpolluted name-space (and if you
enjoy confusing people you can always override the built-ins).

Explicit versus implicit
————————

Related to name-spaces is the notion that Python is explicit: there is very
little magic in a Python script. Perhaps the closest thing to magic are the
various special methods that define a behaviour, for example the `__getattr__`
/ `__setattr__` / `__delattr__` methods on a class to control attribute access.
But even then Python makes it obvious those methods have special meaning by
using a double-underscore for the method names.

See [the page on the data model][special] in the Python documentation for
a description of these methods and their purpose.

Generators and list comprehensions
———————————-

I never realized how much I missed these until I went back to PHP for a small
web project. So much of my code seems to be looping through lists and
accumulating a result or applying a function to each member of the list. I
don’t think the syntax is particularly obvious, but then I can’t think of a
better way to do it. At first glance generators looked to be the same as
list comprehensions, but eventually I began to understand the difference
between needing a finite list of objects ([list comprehension][listcomp])
and consuming a sequence of objects ([generators][generators]).

Named arguments for methods and functions
—————————————–

Gosh, not having named arguments is painful. As a consumer, named arguments
allow one to forget a function’s precise argument signature, and as a
designer it allows one to provide sensible defaults and flexibility.

Dates and times as a native type
——————————–

Well, not _native_, but readily available.

[Python’s `datetime` module][datetime] provides representations of calendar
dates and times and a bunch of obvious behaviour for comparing two moments.
PHP 5 introduced a proper DateTime class, but I had jumped ship a while
before then – my affection for Python’s date handling is borne of a time
when one had to rely on PEAR for useful date functions. Converting everything
to seconds since the Unix epoch was never fun.

The greatest annoyance in Python’s date implementation is its shrugging
support for timezones – you nearly always need to resort to a third-party
module ([such as pytz][pytz] or [python-dateutil][dateutil]) to handle
timezones without jeopardizing one’s sanity.

Batteries included
——————

It is odd that one _does_ need an additional module to handle timezones
seeing as the Python standard library includes so many useful modules for
common tasks.

Need to work with [CSV files][csv]? Or [command-line arguments][getopt]?
Or [Mac OS X-style .plist][plistlib] files? Or configuration files in
[INI format][ini]? Or [tar archives][tar] (with gzip or bzip2 compression)?

Oh golly so much tedious work has been done for you in the Python standard
library. I suppose this reflects PHP’s emphasis as a scripting language for
the Web versus Python’s use as a general purpose language, but I am very
grateful for that distinction.

[zen]: http://www.python.org/dev/peps/pep-0020/
[special]: http://docs.python.org/reference/datamodel.html#special-method-names
[datetime]: http://docs.python.org/library/datetime.html
[pytz]: http://pytz.sourceforge.net/
[dateutil]: http://labix.org/python-dateutil
[csv]: http://docs.python.org/library/csv.html
[getopt]: http://docs.python.org/library/getopt.html
[plistlib]: http://docs.python.org/library/plistlib.html
[ini]: http://docs.python.org/library/configparser.html
[php]: http://www.php.net/
[plone]: http://plone.org/
[django]: http://www.djangoproject.com/
[trac]: http://trac.edgewall.org/
[python]: http://www.python.org/
[listcomp]: http://docs.python.org/tutorial/datastructures.html#list-comprehensions
[generators]: http://docs.python.org/tutorial/classes.html#generators
[tar]: http://docs.python.org/library/tarfile.html

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