mihai <[EMAIL PROTECTED]> wrote:
>
> This is the code:
>
> begin = select_point()
> if begin == None:
> return
>
> end = select_point()
> while end != None:
> record = Record(begin, end)
> id = add(record)
> begin = end
> end = select_point()
> # here (sometimes) begin has the same value (or points to the
> same object) like end, the newly selected one
>
> Is there a way to see if the names points to the same variables or
> that there are different variables with the same values?
You can check whether two names refer to the same object with the 'is'
operator. So you would use:
if begin is end: continue
to skip over any duplicate
>
> The problem is that the problem is more like an bug,
> it happens only in certain conditions, and I have no idea why.
>
> I have checked the values returned by select_point() and are different
> in all the cases,
> so the problem is with that variables names/values.
Are you sure that nothing you do can change the list of points you are
iterating over: usually iteration returning unexpected duplicates is
because you inserted something new into the middle of the list.
A few other unrelated points: the convention is to use 'is' when
checking for None, and you can reduce the number of calls to
'select_point' if you use the 'iter' function. Putting those together:
begin = select_point()
if begin is None:
return
for end in iter(select_point, None):
if begin is end:
continue
record = Record(begin, end)
id = add(record)
begin = end
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