raisePsspyError.py

import psspy
psspy.throwPsseExceptions = True

def ierr_doc(psspyFunc, ierr):
    if not ierr:
        return ''
    
    # Find all the errors documented in the doc string
    errDoc = psspyFunc.__doc__[psspyFunc.__doc__.find('IERR = 0'):]
    errs = {}
    for errStr in errDoc.split('\n'):
        try:
            errNum = errStr.split('=')[1].strip()[0]
            errDesc = errStr.split('=')[1].strip()[2:]
            errs[int(errNum)] = errDesc
        except:
            pass
    return errs[ierr]

def raisePsspyError(psspyFunc):
    """This decorator changes the default Exception message raised by PSSE to include the
    ierr description given in the function help documentation. """
    def callPsspyFunc(*args, **kwargs):
        try:
            return psspyFunc(*args, **kwargs)
        except psspy.PsseException, e:
            e.apiname = ierr_doc(psspyFunc, e.ierr)
            raise e
        
    return callPsspyFunc

# Apply our decorator to all psspy function which return an ierr
import types
for k,v in vars(psspy).items():
    if isinstance(v, types.FunctionType):
        if 'IERR = 0' in v.__doc__:
            vars(psspy)[k] = raisePsspyError(v)

if __name__ == '__main__':
    psspy.case(r"nonexistantFile.sav")  # Will raise a python exception instead
                                        #  of just going mairly on its way