Need better error messages in python interpreter

[sgpearse]

To reproduce:

1. Import any MayControl file (IE - /glade/p/cisl/vast/vapor/data/Source/CM1/Orf/24Maycontrol/24Maycontrol.04000.000000.nc)
2. Create a new Python script with inputs uinterp, vinterp, and winterp
3. Create an output variable named 'foo'
4. Test/execute the following script:

from vapor_utils import * foo=CurlFinDiff(uinterp, vinterp, winterp, 10000.,10000.,1000.)

Error:

Failed to read variable "foo" at time step (0), and
refinement level (-1) and level-of-detail (-1)
Failed to read region from variable/timestep/level/lod (foo, 0, -1, -1)
Variable foo not produced by script
Vapor 3.5.0.8aef7cce6
OS: Mac OS X 11.6.0

[clyne]

CurlFinDiff() returns a tuple of ndarrays (the components of the curl), not a single array. This is documented as part of the 'calling sequence'. Hence, your script doesn't produce the required output variable, 'foo', of type ndarray/float32.

Nevertheless, I will try to improve the error message generated, and change this to a usability issue.