On Thu, January 15, 2009 6:17 pm, Sturla Molden wrote:
> Is it possible to make f2py raise an exception if a fortran routine
> signals an error?
>
> If I e.g. have
>
> subroutine foobar(a, ierr)
>
> Can I get an exception automatically raised if ierr != 0?
Yes, for that you need to provide your own fortran call code
using f2py callstatement construct. The initial fortran call
code can be obtained from f2py generated <modulename>module.c file,
for instance.
An example follows below:
Fortran file foo.f:
-------------------
subroutine foo(a, ierr)
integer a
integer ierr
if (a.gt.10) then
ierr=2
else
if (a.gt.5) then
ierr=1
else
ierr = 0
end if
end if
end
Generated (f2py -m m foo.f) and then modified signature file m.pyf:
-------------------------------------------------------------------
! -*- f90 -*-
! Note: the context of this file is case sensitive.
python module m ! in
interface ! in :m
subroutine foo(a,ierr) ! in :m:foo.f
integer :: a
integer :: ierr
intent (in, out) a
intent (hide) ierr
callstatement '''
(*f2py_func)(&a, &ierr);
if (ierr==1)
{
PyErr_SetString(PyExc_ValueError, "a is gt 5");
}
if (ierr==2)
{
PyErr_SetString(PyExc_ValueError, "a is gt 10");
}
'''
end subroutine foo
end interface
end python module m
! This file was auto-generated with f2py (version:2_5618).
! See http://cens.ioc.ee/projects/f2py2e/
Build the extension module and use from python:
-----------------------------------------------
$ f2py -c m.pyf foo.f
$ python
>>> import m
>>> m.foo(30)
---------------------------------------------------------------------------
<type 'exceptions.ValueError'> Traceback (most recent call last)
/home/pearu/test/f2py/exc/<ipython console> in <module>()
<type 'exceptions.ValueError'>: a is gt 10
>>> m.foo(6)
---------------------------------------------------------------------------
<type 'exceptions.ValueError'> Traceback (most recent call last)
/home/pearu/test/f2py/exc/<ipython console> in <module>()
<type 'exceptions.ValueError'>: a is gt 5
>>> m.foo(4)
4
HTH,
Pearu
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