Octal number problem
staschuk at telusplanet.net
Thu Feb 20 08:22:49 CET 2003
Quoth Carlos Ribeiro:
> On Wednesday 19 February 2003 23:34, Chad Netzer wrote:
> > yes; eval("010") == 8
> > however,
> > int("010") = 10
> I may be mistaken (and someone probably will be more than happy to tell me
> why), but this inconsistence alone seems like a good reason to deprecate
> octals (if only in Python 3000!). It really makes no sense to have
> eval("010") != int("010").
Well, it makes sense to me, for whatever that's worth.
A user-typed string probably demands the decimal interpretation,
because users generally don't know any other base. Likewise for
human-readable data formats which might have prepended zeroes for,
say, sorting purposes.
For the programmer who's doing bit manipulations, however, octal
and hex notations are very useful. For example,
x & 0x0ff0
obviously extracts eight contiguous bits from x, while the decimal
x & 4080
is somewhat mysterious. (For a real-life case, consider a UTF-8
So, having the parser do something different than int() makes
sense; they have different audiences, with different needs.
Steven Taschuk "The world will end if you get this wrong."
staschuk at telusplanet.net (Brian Kernighan and Lorrinda Cherry,
"Typesetting Mathematics -- User's Guide")
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