<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def progress(byte, total, extra=""):
 """ Print some info about how much we have downloaded """

    if total == 0:
        progresstr = "Downloaded %dkB bytes" % (byte >> 10)
        progress_stream.write(progresstr + '\r')
        return
    progressbar(total, byte, extra)