How can I catch segmentation fault in python?

justin justpark78 at
Wed Nov 17 15:28:36 CET 2010

On Nov 17, 1:06 am, John Nagle <na... at> wrote:
> On 11/16/2010 10:15 PM, swapnil wrote:
> > On Nov 17, 10:26 am, justin<justpar... at>  wrote:
> >> Hi all,
> >> I am calling a program written in C inside Python using ctypes,
> >> and it seems that sometimes the program in C crashes while it's being
> >> used in Python.
> >> Even under the circumstances, I want to get the Python program going
> >> by handling the segmentation fault.
> >> I've already searched the Internet, but couldn't get the right answer
> >> to catch them.
> >> Could any of you please let me know how to deal with this and catch
> >> the segmentation fault in Python?
> >> Thanks,
> >> Justin.
> > Segmentation fault isn't exactly an exception that you can catch. It
> > usually means something has gone horribly wrong, like dereferencing
> > invalid pointer, trying to access memory out of process's range. Since
> > if you run out of memory Python simply raises MemoryError exception,
> > which you can catch. So that is not the case for segmentation fault.
>     Either fix the program so it doesn't crash,or run the offending
> module and the C code in a subprocess.
>                                 John Nagle

Thanks guys for this fast replies,

Turns out that it is a fact that segmentation fault is not what I can
deal with in programming level.
But the problem is that the code is not mine, and it takes over a day
for me to get the point where the segmentation fault occurred.
Plus, it seems that the point is not deterministic

Still, I think I should at least try to figure out exactly at which
point the segmentation fault occurs, and think where to go from there
according to your kind advice.

Again many thanks,

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