A new standard module, as discussed on comp.lang.python, to simplify

the writing of filters.

Typical use is:

    import fileinput
    for line in fileinput.input():
        process(line)

This iterates over the lines of all files listed in sys.argv[1:],
defaulting to sys.stdin if the list is empty or when a filename is
'-'.

There is also an option to use this to direct the output back to the
input files.