"Usability, the Soul of Python"

Alf P. Steinbach alfps at start.no
Tue Mar 30 13:40:22 CEST 2010

* Jean-Michel Pichavant:
> John Nagle wrote:
>> Jonathan Hayward wrote:
>>> I've posted "Usability, the Soul of Python: An Introduction to the
>>> Python Programming Language Through the Eyes of Usability", at:
>>>    http://JonathansCorner.com/python/
>>    No, it's just a rather verbose introduction to Python, in dark brown
>> type on a light brown background.  One could write a good paper on this
>> topic, but this isn't it.
>>                 John Nagle
> Why is it bad ?


 From a usability standpoint, the braces go with the lines to print out the 
stanza rather than the for statement or the code after, so the following is best:

for(i = 99; i > 0; ++i)
     printf("%d slabs of spam in my mail!\n", i);
     printf("%d slabs of spam,\n", i);
     printf("Send one to abuse and Just Hit Delete,\n");
     printf("%d slabs of spam in my mail!\n\n", i + 1);

This is just unsubstantiated opinion, but worse, it makes a tacit assumption 
that there is "best" way to do indentation. However, most programmers fall into 
that trap, and I've done it myself. In fact, when I worked as a consultant (then 
in Andersen Consulting, now Accenture) I used the style above. Petter 
Hesselberg, author of "Industrial Strength Windows Programming" (heh, I'm 
mentioned) asked my why on Earth I did that, like, nobody does that? It was a 
habit I'd picked up in Pascal, from very naïve considerations of parse nesting 
levels, a kind of misguided idealism instead of more practical pragmatism, but 
since I realized that that was an incredibly weak argument I instead answered by 
pointing towards Charles Petzold's code in his "Programming Windows" books. And 
amazingly I was allowed to continue using this awkward and impractical style.

I may or may not have been responsible for the similarly impractical compromise 
convention of using three spaces per indentation level. At least, in one big 
meeting the question about number of spaces was raised by the speaker, and I 
replied from the benches, just in jest, "three!". And that was it (perhaps).


- Alf  (admitting to earlier mistakes)

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