Hi, I have a text file with some lines in it. Now I want to iterate over this file and exchange some lines with some others. I tried this approach:
try: myfile= file('myfile', 'r+') while 1: line= myfile.readline() if not line: break l= line.strip().split() if len(l) == 1: hostname= l[0] myfile.write(hostname+' '+mac+'\n') break finally: if not myfile is None: myfile.close() This should inspect the file and find the first line, that can't be split into two parts (that means, which has only one word in it). This line should be exchanged with a line that contains some more info. Unfortunately (or how better python programmers than I am would say, "of course") this doesn't work. The line is exchanged, but also some more lines. Now how can I achieve, what I want? Really exchange one line with another, regardless of their length. Is this possible? If this is not possible, then what would be the best approach to do this? I do not want to read the whole file, exchange the line in memory and then write the whole file. This would be quite slow with large files. Regard1s Marco -- http://mail.python.org/mailman/listinfo/python-list