misc: Add try except except to petsctools import with get_petscvariables

Author: ZoeLeibowitz

devito/petsc/config.py

@@ -2,7 +2,13 @@
 import ctypes
 from pathlib import Path
 
-from petsctools import get_petscvariables, MissingPetscException
+try:
+    from petsctools import get_petscvariables, MissingPetscException
+    petsc_variables = get_petscvariables()
+except ImportError:
+    petsc_variables = {}
+except MissingPetscException:
+    petsc_variables = {}
 
 from devito.tools import memoized_func
 
@@ -46,12 +52,6 @@ def core_metadata():
     }
 
 
-try:
-    petsc_variables = get_petscvariables()
-except MissingPetscException:
-    petsc_variables = {}
-
-
 def get_petsc_type_mappings():
     try:
         petsc_precision = petsc_variables['PETSC_PRECISION']