Packet Validation - Python 2 to 3 update

[JimHofman]

In tlm.py, the validate() functions declared in the FieldDefinitions and DerivationDefinition classes need to modified to fix the 'else' statement of following block (found in both methods):

    if self.enum:
        if value not in self.enum.values():
            valid = False
            flds = (self.name, str(value))
            log("%s value '%s' not in allowed enumerated values." % flds)
        else:
            primitive = int(self.enum.keys()[self.enum.values().index(value)])

The index() method is not a valid method on the enum object.

'self.enum' is a dict:
FieldDefinition(_bytes=0, desc='Distinguishes between core and p...', dntoeu=None, enum={0: 'Core', 1: 'Payload'},

That line will have to be rewritten.

The following script will cause the problem:

import ait.core.tlm as tlm
tlm_dict = tlm.getDefaultDict()
ccsds_pkt_def = tlm_dict['CCSDS_HEADER']
data = bytearray(b'\x01\x02\x03\x04\x05\x06\x07')
ccsds_pkt = tlm.Packet(ccsds_pkt_def, data=data)
test = ccsds_pkt.validate(messages='test validate')