Your semantic for the cb name seems kind of arbitrary. Why is it called for each line of the output and only once with all the output. Plus, iterating through the output line for line can make it much slower than reading it all at once. Also, the next time you run getstatusoutput(), maybe even from another module, the callback will still be called. That could be unexpected. Plus commands is almost deprecated in favour of subprocess. I recommend rejecting this patch.