<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def left_zero_pad(s, blocksize):
 """ Left padding with zero bytes to a given block size :param s: :param blocksize: :return: """

    if blocksize > 0 and len(s) % blocksize:
        s = (blocksize - len(s) % blocksize) * b('\000') + s
    return s