reader = csv.DictReader(f)

    return sort_records([standardize_statement_record(row, reader.line_num) for row in reader])

def standardize_amex_record(row: Dict, line: int) -> Dict:

    """Turn an AMEX CSV row into a standard dict format representing a transaction."""

def match_statement_and_books(statement_trans: list, books_trans: list):

    """

    Runs through all the statement transactions to find a matching transaction

    in the books. If found, the books transaction is marked off so that it can

    only be matched once. Some transactions will be matched, some will be on the

    statement but not the books and some on the books but not the statement.

    """

    matches = []

    remaining_books_trans = []

                best_match_index = i

                best_match_note = note

        if best_match_score > 0.5 and matches_found == 1 and 'check-id mismatch' not in best_match_note or best_match_score > 0.8:

            matches.append(([r1], [books_trans[best_match_index]], best_match_note))

            # Don't try to make a second match against this books entry.

            del books_trans[best_match_index]