Alan Gauld wrote: > "Ricardo Aráoz" <[EMAIL PROTECTED]> wrote > >>>>> In = open(r'E:\MyDir\MyDoc.txt', 'rb') >>>>> Out = open(r'E:\MyDir\MyUpperDoc.txt', 'wb') >>>>> Out.write(In.read().upper()) >>>>> In.close() >>>>> Out.close() >> Pretty simple program. The question is : If 'In' is a HUGE file, how >> does Python process it? > > Exactly as it does for a small file... :-) > >> Does it treat it as a stream and passes bytes to >> 'Out' as soon as they are coming in, or does it read the whole file >> into >> memory and then passes the whole file to 'Out'? > > You have told it to do the latter. > read() reads the whole file into a string so > > Out.write(In.read().upper()) > > Is exactly the same as > > temp = In.read() > temp = temp.upper() > Out.write(temp) > > Just because you put it in one line doesn't chanhge how > Python interprets it. > >> If the answer is the first choice I would like to know how to >> instruct >> Python to do the second choice. > > I'm guessing you mean this the other way around? > > You can read the file line by line > > for line in In: > Out.write(line.upper()) > > HTH,
Thanks a lot. _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
