Correct way to change bytes in a file?

[zivoni]

You can use bytearray instead of list (bytearray is mutable version of bytes and has some useful functions).

with open('data.data', 'rb') as f:
    data = bytearray(f.read())

data[:2] = 0, 0

with open('data.data', 'wb') as f:
    f.write(data)