...okay, two options I can see:

1)  Use JSON format, and native python ``json.loads()`` to convert JSON-string into a list-of-dicts for you.
2)  Unroll the dictionaries and lists, so:

     invalid_run_params = {"InvalidPars":[["^"],["@"],["ABC"]],"InvalVals":[["abc"],["a-b-c"],["abc123"],["abc_123"]]}

would become

     invalid_run_params = ^,@,ABC
     invalid_run_values = abc,a-b-c,abc123,abc_123

where it converts into a list easily in test code like:

    invalid_run_values = self.config['invalid_run_values'].strip().split(',')

I'd suggest the later (comma-separated) since it's used in many other tests also.