Function create_data

qrcode/util.py:550–584

(version, error_correction, data_list)

def create_data(version, error_correction, data_list):
    buffer = BitBuffer()
    for data in data_list:
        buffer.put(data.mode, 4)
        buffer.put(len(data), length_in_bits(data.mode, version))
        data.write(buffer)

    # Calculate the maximum number of bits for the given version.
    rs_blocks = base.rs_blocks(version, error_correction)
    bit_limit = sum(block.data_count * 8 for block in rs_blocks)
    if len(buffer) > bit_limit:
        raise exceptions.DataOverflowError(
            "Code length overflow. Data size (%s) > size available (%s)"
            % (len(buffer), bit_limit)
        )

    # Terminate the bits (add up to four 0s).
    for _ in range(min(bit_limit - len(buffer), 4)):
        buffer.put_bit(False)

    # Delimit the string into 8-bit words, padding with 0s if necessary.
    delimit = len(buffer) % 8
    if delimit:
        for _ in range(8 - delimit):
            buffer.put_bit(False)

    # Add special alternating padding bitstrings until buffer is full.
    bytes_to_fill = (bit_limit - len(buffer)) // 8
    for i in range(bytes_to_fill):
        if i % 2 == 0:
            buffer.put(PAD0, 8)
        else:
            buffer.put(PAD1, 8)

    return create_bytes(buffer, rs_blocks)