Chris Rebert wrote:
On Tue, Nov 24, 2009 at 9:39 AM, Ethan Furman <et...@stoneleaf.us> wrote:
Bruno Desthuilliers wrote:
Ethan Furman a écrit :
The problem I have with properties is my typing. I'll end up assigning
to an attribute, but get the spelling slightly wrong (capitalized, or
missing an underscore -- non-obvious things when bug-hunting), so now I have
an extra attribute which of course has zero effect on what I'm trying to do
and I start getting wierd results like viewing deleted records when I *know*
I set useDeleted = False... 30 minutes later I notice it was /supposed/ to
be use_deleted. *sigh*
So -- to keep myself out of trouble -- I have started coding such things
as, for example:
result = table.use_deleted() # returns True or False
table.use_deleted(False) # skip deleted records
instead of
result = table.use_deleted
table.use_deleted = False
My question: is this [ severely | mildly | not at all ] un-pythonic?
Definitly and totally unpythonic. The first solution to your problem is to
stick to standard naming conventions. If this is not enough, Chris pointed
you to really useful tools. Also, you can override __setattr__ to catch such
errors - at least during the coding/debug phase.
Good tools to know about, and a consistent naming pattern also makes life
easier (which I have since done ;).
Let's head towards murkier waters (at least murkier to me -- hopefully they
can be easily clarified): some of the attributes are read-only, such as
record count; others are not directly exposed, but still settable, such as
table version; and still others require a small amount of processing... at
which point do I switch from simple attribute access to method access?
Thanks to the magic of properties, the end-user-programmer need not
know which you're using:
http://docs.python.org/library/functions.html#property
You know, when I first read that bit on properties a while back, the
explanation of the decorators and how a property was also a decorator
for the setter and deleter bits completely lost me. Since then I've
played with decorators a bit, written a configaration module that uses
them, and just now, reading the description... it was so elegantly
simple it almost brought tears to my eyes *sniff*. I love Python.
Okay, I'll go back and switch all my attributes *back* to attributes --
and properties will be much nicer than my original implementation (using
__getattr__ and __setattr__).
Many thanks to all who answered!
~Ethan~
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