line-by-line output from a subprocess

[Simon Percivall]

Okay, so the reason what you're trying to do doesn't work is that the
readahead buffer used by the file iterator is 8192 bytes, which clearly
might be too much. It also might be because the output from the
application you're running is buffered, so you might have to do
something about that as well.

Anyway, if the output from the child application is unbuffered, writing
a generator like this would work:

def iterread(fobj):
    stdout = fobj.stdout.read(1) # or what you like
    data = ""
    while stdout:
        data += stdout
        while "\n" in data:
            line, data = data.split("\n", 1)
            yield line
        stdout = fobj.stdout.read(1)
    if data:
        yield data,