On Jan 7, 9:41 pm, Dennis Lee Bieber <[EMAIL PROTECTED]> wrote: > On Mon, 7 Jan 2008 20:10:58 -0800 (PST), "Russ P." > <[EMAIL PROTECTED]> declaimed the following in comp.lang.python: > > > for file0 in files: > > > lnum = 0 # line number > > > for line in file(file0): > > lnum += 1 > > if lnum >= 4: break > > > # do something with "line" > > > where "files" is a list of the files to be read. > > Given that the OP is talking 2000 files to be processed, I think I'd > recommend explicit open() and close() calls to avoid having lots of I/O > structures floating around... > > for fid in file_list: > fin = open(fid) > jnk = fin.readline() > jnk = fin.readline() > jnk = fin.readline() > ln = fin.readline() > fin.close() > > Yes, coding three junk reads does mean maintenance will be a pain > (we now need the 5th line, not the fourth -- and would need to add > another jnk = line)... I'd maybe consider replacing all four readline() > with: > > for cnt in xrange(4): > ln = fin.readline() > > since it doesn't need the overhead of a separate line counter/test and > will leave the fourth input line in "ln" on exit. > -- > Wulfraed Dennis Lee Bieber KD6MOG > [EMAIL PROTECTED] [EMAIL PROTECTED] > HTTP://wlfraed.home.netcom.com/ > (Bestiaria Support Staff: [EMAIL PROTECTED]) > HTTP://www.bestiaria.com/
One second thought, I wonder if the reference counting mechanism would be "smart" enough to automatically close the previous file on each iteration of the outer loop. If so, the files don't need to be explicitly closed. -- http://mail.python.org/mailman/listinfo/python-list
