[issue22683] bisect index out of bounds issue

2014-10-31 Thread Raymond Hettinger 

Raymond Hettinger added the comment:

 treat the hi in the precondition in the same way as the lo parameter

Originally, there was no special test for lo.  The test was added only because 
negative lo value failed in an unfortunate way (with an infinite loop).  No 
change to hi was made because (it succeeded in some cases and existing code 
might be relying on that or it failed in clear-cut way by raising an 
IndexError).

 That being said, from my point of view this ticket can be closed.

I concur.  When there isn't a clear case for change, it is usually better to 
favor stability over potential disruption.

--
resolution:  - rejected
status: open - closed

___
Python tracker rep...@bugs.python.org
http://bugs.python.org/issue22683
___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue22683] bisect index out of bounds issue

2014-10-23 Thread Paul Ianas 

Paul Ianas added the comment:

Sure, it is your call. As said, this is rather an enhancement.

Still, if I were to decide, I would chose:
1. not to break the API = raise IndexError instead of ValueError in case hi 
is invalid.
2. to protect against illegal values: as said, if hi  0 bisect_* always 
returns 0 (whatever the searched value).
3. I would implement a single _range_check(_len, lo, hi) method to do this 
logic (DRY).

That being said, from my point of view this ticket can be closed.

--

___
Python tracker rep...@bugs.python.org
http://bugs.python.org/issue22683
___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue22683] bisect index out of bounds issue

2014-10-22 Thread Raymond Hettinger 

Changes by Raymond Hettinger raymond.hettin...@gmail.com:


--
assignee:  - rhettinger

___
Python tracker rep...@bugs.python.org
http://bugs.python.org/issue22683
___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue22683] bisect index out of bounds issue

2014-10-22 Thread Raymond Hettinger 

Raymond Hettinger added the comment:

These functions are very old and the API is unlikely to change, particularly if 
the goal is to change one kind of exception to another (making bad inputs fail 
in a different way than they do now).  As far as I can tell, the current 
arrangement has never been a actual problem in practice.

--
versions:  -Python 2.7, Python 3.2, Python 3.3, Python 3.4

___
Python tracker rep...@bugs.python.org
http://bugs.python.org/issue22683
___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue22683] bisect index out of bounds issue

2014-10-21 Thread Paul Ianas 

New submission from Paul Ianas:

The precondition for all the bisect functions is implemented like this:

if lo  0:
raise ValueError('lo must be non-negative')
if hi is None:
hi = len(a)

Now, of course, if hi is given, and hi = 2 * len(a), then we get an 
IndexError. In case hi  0, we always get 0 as a result (even if the element is 
there).

I think it would be better to treat the hi in the precondition in the same way 
as the lo parameter: that means, raise a ValueError in case hi has an illegal 
value.

Disclaimer: of course, it makes no sense to give an illegal argument to that 
function; still, since lo is treated against illegal values, maybe it's better 
to do the same for hi.

At the same time, maybe moving the precondition code in a separate function 
(which raises a ValueError in case precondition is not met) makes more sense, 
for not repeating the same code in all bisect functions.

A small snippet which reproduces this:

from bisect import bisect_left

a = [1, 2, 3, 4]
idx = bisect_left(a, 2, 0, 10)  # 10  2 * 4
print(idx)

--
components: Library (Lib)
messages: 229750
nosy: Paul.Ianas
priority: normal
severity: normal
status: open
title: bisect index out of bounds issue
type: enhancement
versions: Python 2.7, Python 3.2, Python 3.3, Python 3.4, Python 3.5

___
Python tracker rep...@bugs.python.org
http://bugs.python.org/issue22683
___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue22683] bisect index out of bounds issue

2014-10-21 Thread Antoine Pitrou 

Changes by Antoine Pitrou pit...@free.fr:


--
nosy: +rhettinger, tim.peters

___
Python tracker rep...@bugs.python.org
http://bugs.python.org/issue22683
___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com