As I said I am no expert in OS and commands, except on what concerns mechanical statistical and quantum mechanical calculations. Therefore, better for me (and for all guys here) if I stop on this matter. My reply is only to say that I did the job with:
f=open("prod1-3_no_wat_pop.pdb", "r") for line in f: line=line.rstrip() if "WAT" not in line: print line f.close() It took time on the billion lines to write, though it worked. About grep may be you are right. At any event, in my job I never edit a file without saving a separate copy of the original. Think that I'll never carry out a computation (that may last weeks) without a raid 1 system. Not to mention certain commercial OS that are carefully avoided for calculations (in my office for everything), also because they need to emulate unix to do that. cheers francesco --- Steven D'Aprano <[EMAIL PROTECTED]> wrote: > On Mon, 07 Jan 2008 00:42:01 +0000, Grant Edwards wrote: > > >> If you want to delete them, you still have to do the rest of the job > >> yourself. > > > > Nonsense. > > > > How is this not doing what the OP asks? > > > > grep -v pattern infile >outfile; mv outfile infile > > It isn't deleting lines. As abstractions go, it comes pretty close, but > just try it on a disk with insufficient free space for the temporary > outfile and watch it break. > > > -- > Steven > -- > http://mail.python.org/mailman/listinfo/python-list > ____________________________________________________________________________________ Looking for last minute shopping deals? Find them fast with Yahoo! Search. http://tools.search.yahoo.com/newsearch/category.php?category=shopping -- http://mail.python.org/mailman/listinfo/python-list