autoself: automagically add method definition boilerplate
First, a disclaimer. Explicit self is good. Bytecode hacks are bad.
Put them together and it's quite clear that THIS MODULE IS AN ABOMINATION!
But, it's a neat excursion into python's lower levels and if you *really*
*really* want to save yourself some keystrokes (like, you're desperately
trying to hack into the Death Star's security system to override the trash
compactor as its cold metal jaws slowly squeeze you to a purple paste) then
it can help you do that. But, stop and consider Guido's proclamation on
the matter:
Having self be explicit is a *good thing*. It makes the code clear by
removing ambiguity about how a variable resolves. It also makes the
difference between functions and methods small.
"Things that will Not Change in Python 3000":
http://www.python.org/dev/peps/pep-3099/#core-language
This module is not about making 'self' implicit. It doesn't try to change
the way methods work, or make any semantic changes whatsoever. It does one
simple thing: automatically adds the boilerplate code to make a function do
the "right thing" when called as a method.
It provides a single function 'autoself'. Given a function as argument,
'autoself' will return an equivalent function with the necessary boilerplate
in place to act as a method. This will depend on the specifics of the
function, and could mean:
* Inserting 'self' as the zeroth argument
* Inserting 'cls' as the zeroth argument, and wrapping with classmethod()
* Wrapping with staticmethod() if 'self' and 'cls' are not used
* Doing nothing, if it's not a proper function or is fine the way it is
For example, defining the method 'likes' using:
def likes(self,ham,eggs):
print self, "likes", ham, "and", eggs
Is equivalent to defining it in the following way:
def likes(ham,eggs):
print self, "likes", ham, "and", eggs
likes = autoself(likes)
Or neater, using the @autoself decorator. Of course, this isn't going to
save you any typing! 'autoself' can also be applied to a class, and will
autoselfify all functions in that class's dict:
class HeapsLessTyping:
def likes(ham,eggs):
# This gets 'self' automatically added as zeroth argument
print self, "likes", ham, "and", eggs
def hates(spam):
# This becomes a classmethod, with 'cls' added as zeroth argument
print "all", cls, "hate", spam
def meh(toast):
# This becomes a staticmethod
print toast, "is boring"
HeapsLessTyping = autoself(HeapsLessTyping)
When it becomes available (Python 2.6?), it will be even more convenient to
use this with the class decorator syntax.
Want to save even more typing? 'autoself' can be used as a metaclass to
work its magic on all classes defined in a module:
__metaclass__ = autoself
class LookNoSelf:
def __init__(my,special,args):
self.my = my
self.special = special
self.args = args
class FiveKeystrokesSaved:
def __init__(this,works,great):
self.this = this
self.works = works
self.great = great
counter = 0
def ClassMethodsSaveEvenMore():
cls.counter += 1
Using this style, you can see a net saving in keystrokes with five method
definitions or less!
