read the bias file based on the short_filename
        and return as a dictionary

def _read_bias_rating(self, short_filename):
        """
        read the bias file based on the short_filename
        and return as a dictionary
        """
        res = {}
        full_name = os.path.join(root_fldr, 'aikif', 'data', 'ref', short_filename)
        lg.record_process('bias.py','reading ' + full_name)
         
        with open(full_name, 'r') as f:
            for line in f:
                if line.strip('') == '':
                    break
                bias_line = []
                cols = line.split(',')
                bias_line.extend([short_filename])
                for col in cols:
                    bias_line.extend([col.strip('"').strip('\n')])
                self.bias_details.append(bias_line)