[Edu-sig] spinning 'self'
kirby.urner at gmail.com
Mon Aug 13 22:43:20 CEST 2007
Python is remarkably liberal in its design, in that 'self' is not a
keyword. You're free to use other names for this important
place in memory.
Yet there's still self-imposed discipline (another way of saying
'self discipline'), such that we tend to all use 'self' anyway, by
convention (but Python-the-interpreter doesn't complain if we
don't -- not likely to change).
However, as Python teachers have widely remarked, this concept
of 'self' is not easily communicated at first, given the OO paradigm
is itself still coming into focus for some students.
In the class definition, the 'self' is really a 'place holder' (akin to zero)
i.e. it doesn't do any work, but keeps a place open, like a driver's
seat waiting for a driver.
When an *object* of said class is created, the self becomes
specified, as a kind of *anchor*. And plumbing the depths of
'self' is easy: all you need is __dict__ (i.e. a self is basically
another namespace, a concept already familiar from earlier
Python-by-comic-book (including on the net) is an emerging
genre, influenced by Head First, Dive Into, and For Dummies
I'm storyboarding for comics (could be TV shows) in which
' this ', ' me ' and ' ghost ' each get a crack at occupying
the ' self ' position. Each of these English options has its
own logic and connotations.
I especially like ' ghost ' because of its ' ghost in the shell '
connotations (a link to manga, the genre we're in).
As Python goes towards Unicode, other "non-Romanji"
substitutes for ' self ' may suggest themselves.
However (back to self-discipline) I think it's wise to stick
to the guidelines and go with non-idiosyncratic forms.
David Goodger was good on this in his 'Idiomatic Python'
at OSCON 2007 :
If your object is an iterable (i.e. has a "duck face" (which is
like being a "duck type" but sounds more like "interface"))
then address as such, as in in 'for myvar in self.__dict__',
and not using has_key() or some such more specialcase
In this same spirit (aha! another one), we just go with 'self'
at the end of the day.
(theme song choral sequences some of my all time favorites)
Also mentioned in my blogs:
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