Procedures and functions [was Re: Why not allow empty code blocks?]
D'Arcy J.M. Cain
darcy at Vex.Net
Sun Jul 31 00:01:33 EDT 2016
On Sun, 31 Jul 2016 13:32:16 +1000
Steven D'Aprano <steve at pearwood.info> wrote:
> Many beginners make the mistake of writing:
>
> mylist = mylist.sort()
>
> or try to write:
>
> mylist.sort().reverse()
>
> If we had procedures, that would be an obvious error (possibly even a
> compile-time syntax error) instead of a perplexing source of mystery
> bugs.
While neither is a syntax error, the latter is definitely a run-time
error:
>>> mylist.sort().reverse()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AttributeError: 'NoneType' object has no attribute 'reverse'
--
D'Arcy J.M. Cain
System Administrator, Vex.Net
http://www.Vex.Net/ IM:darcy at Vex.Net
VoIP: sip:darcy at Vex.Net
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