Behaviour for sandy.sampling.run() for libraries without covaraince data

[jbae11]

Please note that I'm not too knowledgeable with the code, so feel free to comment angry messages and close the issue if this is in error :)

For example, for ENDF-B-VII.1-neutrons n-008-O_017.endf,

sandy.sampling.run() errors because the get_perturbations() will return an empty dictionary (i.e., smps={}). This will cause the apply_perturbations() function to error with the following error message:

Traceback (most recent call last):
  File "go.py", line 10, in <module>
    obj.run()
  File "/home/4ib/anaconda3/envs/env_neutronics/lib/python3.7/site-packages/fermi-0.1-py3.7.egg/fermi/neutronics/nuclear_data_perturbation/openmc_data_pert.py", line 40, in run
    self.generate_perturbed_data()
  File "/home/4ib/anaconda3/envs/env_neutronics/lib/python3.7/site-packages/fermi-0.1-py3.7.egg/fermi/neutronics/nuclear_data_perturbation/openmc_data_pert.py", line 95, in generate_perturbed_data
    sandy.sampling.run(' '.join(cli))
  File "/home/4ib/anaconda3/envs/env_neutronics/lib/python3.7/site-packages/sandy-1.0.37-py3.7.egg/sandy/sampling.py", line 185, in inner
    foo(iargs)
  File "/home/4ib/anaconda3/envs/env_neutronics/lib/python3.7/site-packages/sandy-1.0.37-py3.7.egg/sandy/sampling.py", line 305, in run
    verbose=iargs.debug,
  File "/home/4ib/anaconda3/envs/env_neutronics/lib/python3.7/site-packages/sandy-1.0.37-py3.7.egg/sandy/core/endf6.py", line 2204, in apply_perturbations
    if not item:
UnboundLocalError: local variable 'item' referenced before assignment

Is there a way to add an argument so that if the file does not have any covariance data it will just output something helpful? Thanks!

[jbae11]

This is what I used, but I feel like it's not the most appropriate:

    if not smps: # covariance data does not exist
        print('Covariance data does not exist!')
        pendf = endf6.get_pendf(**pendf_kws)
        ace = endf6.get_ace(pendf=pendf, **ace_kws)
        suffix = ace_kws.get("suffix", "." + sandy.njoy.get_temperature_suffix(temperature))
        file_name = iargs.outname + suffix + 'c'
        for i in range(iargs.samples):
            fn = file_name.replace('{SMP}', str(i))
            with open(fn, 'w') as f:
                f.write(ace['ace'])
            fn += '.xsd'
            with open(fn, 'w') as f:
                f.write(ace['xsdir'])