How to write bytes object to i2c memory (using i2c.writeto_mem() operation)?

[cole-morrel]

Hello,
I am trying to optimize some older code for memory usage. On an earlier post I made about this I received the suggestion to replace lists in the code like:

OV2640_YUV422 = [
  [ 0xFF, 0x00 ],
  [ 0x05, 0x00 ],
  [ 0xDA, 0x10 ],
  [ 0xD7, 0x03 ],
  [ 0xDF, 0x00 ],
  [ 0x33, 0x80 ],
  [ 0x3C, 0x40 ],
  [ 0xe1, 0x77 ],
  [ 0x00, 0x00 ],
  [ 0xff, 0xff ],
]

with a bytes object like OV2640_YUV422 = b'\xff\x00\x05\x00...' as it would significantly cut down on the memory size. The lists like OV2640_YUV422 are currently being used in this function:

def cam_write_register_set(i, addr, set):
    for el in set:
        raddr = el[0]
        val = bytes([el[1]])
        if (raddr == 0xff and val == b'\xff'):
            return
        i.writeto_mem(addr, raddr, val)

where set is something like OV2640_YUV422, addr is SENSORADDR = 0x30, and i is self.i2c. If I understand this function correctly this means that the left column of OV2640_YUV422 is being stored as raddr, and serving as the memory address in the writeto_mem operation, while the right column is being converted to bytes and stored as val, serving as buf in the writeto_mem operation, and that the function iterates through the list until it reaches the final entry (where raddr == 0xff and val == b'\xff'). So what I'm asking is how to do the same thing (or something similar) when OV2640_YUV422 is in the form b'\xff\x00\x05\x00...' (if that is possible). Please forgive me if this wasn't the clearest, I'm still fairly new to Python and trying to learn.

[rkompass]

I can imagine something like

OV2640_B = (b'\xff\x05\xda\xd7\xdf\x33\x3c\xe1\x00\xff',
            b'\x00\x00\x10\x03\x00\x80\x40\x77\x00\xff')

for maddr, data in zip(OV2640_B[0], OV2640_B[1]):
    if maddr == data == 0xff:
        break
    self.i2c.writeto_mem(iaddr, maddr, bytes(data))

If you should find out that the \xff bytes combo is only found at the end of the data then you may omit the test for it with the break statement (and the pair of \xff's), as the for loop is terminating anyway.