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

def get_h2i(self, hdrs_usr):
        """Read csv/tsv file and return specified data in a list of lists."""
        with open(self.fin) as fin_stream:
            for line in fin_stream:
                line = line.rstrip('\r\n') # chomp
                if not self.hdr2idx:
                    if self.do_hdr(line, hdrs_usr):
                        return self.hdr2idx
        return None