Read csv/tsv file and return specified data in a list of lists.

def run(self, fnc_name, hdrs_usr):
        """Read csv/tsv file and return specified data in a list of lists."""
        fnc = self.fncs[fnc_name]
        with open(self.fin) as fin_stream:
            for lnum, line in enumerate(fin_stream):
                line = line.rstrip('\r\n') # chomp
                # Obtain Data if headers have been collected from the first line
                if self.hdr2idx:
                    self._init_data_line(fnc, lnum, line)
                # Obtain the header
                else:
                    self.do_hdr(line, hdrs_usr)
            if self.log is not None:
                self.log.write("  {:9} data READ:  {}\n".format(len(self.ret_list), self.fin))
        return self.ret_list, self.hdr2idx