[Python-Dev] Augmented assignment

[Peter Funk]

Hi,

[...]
[me]:
> > What remains is, that augmented assignments are only a short cut
> > notation, which introduces more variability to express the same
> > algorithms and so they hurt readability.  

[Gordon McMillan]:
> It definitely *improves* the readability of incrementing very-long-
> expression. Just not to the point of readability ;-).

I agree, that very complicated multidimensional expressions, (possible
mixing tuples, lists, dicts and computations) are even more errorprone
, if you have to repeat them twice just to increment an element.
But than you would use an helper variable to hold the index expression
anyway.

example:

   foo = range(3); bar = range(3); cols = ('red', 'green', 'blue')
   chans = {'red':2, 'green':1, 'blue':0}

   foo[chans[cols[2-bar[0]]]] = foo[chans[cols[2-bar[0]]]] + 1

is indeed ugly.  But

   i = chans[cols[2-bar[0]]]; foo[i] = foo[i] + 1

is at least just as (un)readable as 

   foo[chans[cols[bar[0]]]] += 1

with the exception, that even newbies get a chance to figure out, 
what the former line is supposed to do without having to read a language 
reference manual telling them something about augmented assignments.

But you are right:  This has been discussed often enough on c.l.p.

Regards, Peter
-- 
Peter Funk, Oldenburger Str.86, D-27777 Ganderkesee, Germany, Fax:+49 4222950260
office: +49 421 20419-0 (ArtCom GmbH, Grazer Str.8, D-28359 Bremen)