>>> huge = io.open("C:\HUGE_FILE.pcl",'r+b',0) Why do you want to disable buffering? From the io.open help:
open(file, mode='r', buffering=None, encoding=None, errors=None, newline=None, closefd=True) Open file and return a stream. Raise IOError upon failure. ... buffering is an optional integer used to set the buffering policy. By default full buffering is on. Pass 0 to switch buffering off (only allowed in binary mode), 1 to set line buffering, and an integer > 1 for full buffering. I think you will get better performance if you open the file without the third arg: huge = io.open("C:\HUGE_FILE.pcl",'r+b') -- Skip Montanaro - [EMAIL PROTECTED] - http://smontanaro.dyndns.org/ -- http://mail.python.org/mailman/listinfo/python-list