[Edu-sig] Design patterns

Arthur ajsiegel at optonline.net
Sun Aug 21 21:09:42 CEST 2005



> -----Original Message-----
> From: edu-sig-bounces at python.org [mailto:edu-sig-bounces at python.org] On
> Behalf Of Scott David Daniels
> 
> I'd propose two reasons why properties are so successful.
> 
> The first explanation comes from eXtreme Programming.  One big goal of
> XP is to stop wasting time doing "big design up front." 

Then my situation is a bit ironic. What I don't seem to have realized - at
least to my own satisfaction - is some rational scheme for the use of
properties.  They are used - somewhere in the range from haphazardly to
intuitively.  So I am left to refactor working code to give some scheme to
my use of properties.  And since this refactoring is coming at a fairly late
stage of design, I don't feel the same need to leave my XP options open to
the extent that I might had I thought more thoroughly about the use of
properties earlier in the process.  So where I come out on the use of
properties now might not be the same as where I would have come out at some
different point.

Why do I find this unsatisfying? 

As an API matter, I find myself liking the clue that "()" provides as to
whether one is accessing something designed be determined dynamically.  So I
find myself leaning towards the option of making the use of properties go
away in PyGeo.  


Art




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