tail -f in python with no time.sleep

Question

I need to emulate \"tail -f\" in python, but I don\'t want to use time.sleep in the reading loop. I want something more elegant like some kind of blocking read, or select.se

Answer 1

To minimize the sleep issues I modified Tzury Bar Yochay's solution and now it polls quickly if there is activity and after a few seconds of no activity it only polls every second.

import time

def follow(thefile):
    thefile.seek(0,2)      # Go to the end of the file
    sleep = 0.00001
    while True:
        line = thefile.readline()
        if not line:
            time.sleep(sleep)    # Sleep briefly
            if sleep < 1.0:
                sleep += 0.00001
            continue
        sleep = 0.00001
        yield line

logfile = open("/var/log/system.log")
loglines = follow(logfile)
for line in loglines:
    print line,