## gen() function for proc.stdout ( run_commands, vdl_run ) ## async read from proc.stdout

proc_stdout_gen.py

## gen() function for proc.stdout ( run_commands, vdl_run )
## async read from proc.stdout
if True:
    def gen(proc):
        remains = b''  # remaining from prev read
        while proc.poll() is None:
            rlist, _, _ = select([proc.stdout],[],[],500)
            if proc.stdout not in rlist:
                continue
            data = os.read(proc.stdout.fileno(), 16384)
            if not data: ## EOF (empty bytes)
                if remains:  # flush remains, if exists
                    yield _decode(remains)
                if verbose:
                    print('\n\ngen([%d]): EOF'.format(proc.pid))
                break # break loop after flush
            data = remains + data
            remains = b''
            for ln in data.splitlines(keepends=True):
                if ln.endswith(b'\n'):
                    yield _decode(ln)
                else:
                    remains = ln
        try:
            outs, errs = proc.communicate()
            yield _decode(outs)
            if errs:
                yield _decode(errs)
        except ValueError:  # I/O operation on closed file // PyMemoryView_FromBuffer(): info->buf must not be NULL
            pass
        assert proc.returncode == 0, ('subprocess exit with:', proc.returncode)
        return