On Aug 8, 2:35 am, Paul Rubin <http://[EMAIL PROTECTED]> wrote: > Sullivan WxPyQtKinter <[EMAIL PROTECTED]> writes: > > This program: > > for i in range(1000000000): > > f.readline() > > is absolutely every slow.... > > There are two problems: > > 1) range(1000000000) builds a list of a billion elements in memory, > which is many gigabytes and probably thrashing your machine. > You want to use xrange instead of range, which builds an iterator > (i.e. something that uses just a small amount of memory, and > generates the values on the fly instead of precomputing a list). > > 2) f.readline() reads an entire line of input which (depending on > the nature of the log file) could also be of very large size. > If you're sure the log file contents are sensible (lines up to > several megabytes shouldn't cause a problem) then you can do it > that way, but otherwise you want to read fixed size units.
Thank you for pointing out these two problem. I wrote this program just to say that how inefficient it is to use a seemingly NATIVE way to seek a such a big file. No other intention........ -- http://mail.python.org/mailman/listinfo/python-list
