[petsc-users] Options database in petsc4py

[SCOTTO Alexandre]

In if this is a bug, I think the fix you proposed should also be applied to the destroy() method, as it does not clear the database either.

Regards,
Alexandre.

De : Pierre Jolivet <pierre at joliv.et>
Envoyé : lundi 27 octobre 2025 10:36
À : SCOTTO Alexandre <alexandre.scotto at irt-saintexupery.com>
Cc : petsc-users at mcs.anl.gov
Objet : Re: [petsc-users] Options database in petsc4py

I would say this is a bug in petsc4py, the following diff should fix this.
I’m not sure why this if is there, as it’s perfectly valid to call PetscOptionsClear(NULL).

Thanks,
Pierre

diff --git a/src/binding/petsc4py/src/petsc4py/PETSc/Options.pyx b/src/binding/petsc4py/src/petsc4py/PETSc/Options.pyx
index 4db3c52f022..8a923a6dd8e 100644
--- a/src/binding/petsc4py/src/petsc4py/PETSc/Options.pyx
+++ b/src/binding/petsc4py/src/petsc4py/PETSc/Options.pyx
@@ -90,7 +90,6 @@ cdef class Options:

     def clear(self) -> Self:
         """Clear an options database."""
-        if self.opt == NULL: return
         CHKERR(PetscOptionsClear(self.opt))
         return self


On 27 Oct 2025, at 10:23 AM, SCOTTO Alexandre via petsc-users <petsc-users at mcs.anl.gov<mailto:petsc-users at mcs.anl.gov>> wrote:

Dear PETSc Community,

In my developments, I am managing possibly several KSP solvers with options handled by the Options database. During my tests, I encountered the following behavior:

Code:
options = PETSc.Options("ksp_")
options.setValue("atol", 7e-8)
options.view()

options.clear()
options.view()

Output:
#PETSc Option Table entries:
-ksp_atol 7e-08 # (source: code)
#End of PETSc Option Table entries

#PETSc Option Table entries:
-ksp_atol 7e-08 # (source: code)
#End of PETSc Option Table entries

It seems that the clear() method does not really clear the Option database. To ensure that the several KSP I deal with are set with their own options (without getting options from a KSP previously set), the only way I found was to explicitly call the delValue() method for all the option keys passed:

1.       Iterate over a dictionary of options and use setValue(name, value)
2.       Set the KSP with option database: KSP.setFromOptions()
3.       Iterate over a the keys of the dictionary and use delValue(name) to effectively clear the option database.

Does it seem normal to you, is there something I am missing out?

Regards,
Alexandre Scotto.

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