Turn off ZeroDivisionError?

Mark Dickinson dickinsm at gmail.com
Sun Feb 10 23:01:55 CET 2008

On Feb 10, 3:29 pm, Grant Edwards <gra... at visi.com> wrote:
> platform does".  Except it doesn't in cases like this. All my
> platforms do exactly what I want for division by zero: they
> generate a properly signed INF.  Python chooses to override
> that (IMO correct) platform behavior with something surprising.
> Python doesn't generate exceptions for other floating point
> "events" -- why the inconsistency with divide by zero?

But not everyone wants 1./0. to produce an infinity;  some people
would prefer an exception.

Python does try to generate exceptions for floating-point events
at least some of the time---e.g. generating ValueErrors for
sqrt(-1.) and log(-1.) and OverflowError for exp(large_number).

I agree that the current situation is not ideal.  I think the ideal
would be to have a floating-point environment much like Decimal's,
where the user has control over whether floating-point exceptions
are trapped (producing Python exceptions) or not (producing
and nans).  The main difficulty is in writing reliable ANSI C that
can do this across platforms.  It's probably not impossible, but
it is a lot of work.

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