ValueError thrown on specific byte sequence

[adamsqi]

ValueError is thrown in optimal_sequence_to_bits when generating Aztec codes. In MIXED mode there is no coding of the 2-byte sequence b'\r\n'. Below is the thrown error.

File "/usr/local/lib/python3.10/site-packages/aztec_code_generator.py", line 514, in find_suitable_matrix_size
    out_bits = optimal_sequence_to_bits(optimal_sequence)
  File "/usr/local/lib/python3.10/site-packages/aztec_code_generator.py", line 403, in optimal_sequence_to_bits
    index = code_chars[mode].index(ch)
ValueError: b'\r\n' is not in list

@dlenski I've tried to fix this problem myself, but my knowledge of the Aztec algorithm isn't good enough for that.

[jschlyter]

I'm in the same team as @adamsqi and we're suffering a bit from this. Is there anything we can do to move forward @dlenski (except trying to fix find_optimal_sequence that is).

[fgrieu]

My reading is that the change at line 339 (the one commented) is an attempt to fix the present bug.

if last_mode == Mode.PUNCT:
    last_c = cur_seq[x][-1]
    if isinstance(last_c, int) and bytes((last_c, c)) in punct_2_chars:
        if x != Mode.MIXED:  # we need to avoid this because it contains '\r', '\n' individually, but not combined
            if cur_len[x] < next_len[x]:
                next_len[x] = cur_len[x]
                next_seq[x] = cur_seq[x][:-1] + [ bytes((last_c, c)) ]

This comment refers to https://github.com/dlenski/aztec_code_generator/blob/master/aztec_code_generator.py of 2024-12-17