to property or function in class object

Steven Bethard steven.bethard at gmail.com
Fri Aug 17 19:43:35 CEST 2007


james_027 wrote:
> i am very new to python, not knowing much about good design. I have an
> object here for example a Customer object, where I need to retrieve a
> info which has a number of lines of code to get it.
> 
> my question is weather what approach should I use? to use the property
> which is from the python new class style as I understand or simple use
> function that will return the the info I needed.
[snip]
> While both approach would get the job done, I don't know much about
> the performance, benefits, design philosophy between the two approach.

I tend to view property as only something you use for the purposes of 
backwards compatibility. So if you started with something as a simple 
attribute and you later realize that it needs to do some computation, 
you can use properties to keep the same API.

However, if I know right off the bat that I need to do some computation 
to return a result, then I'll always prefer a method.  People expect a 
method call to take some computation.  People don't always expect that 
from a simple attribute access.  So I think it's more predictable for 
your users if you use a method when there's any real work being done.

STeVe



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