In my GSoC project, I have implemented asnychronous I/O in subprocess.Popen. Since the read/write operations are asynchronous, the program may have already exited by the time one calls the asyncread function I have implemented. While it returns the data just fine, I have come across an issue with the TerminateProcess function in Windows: if the program has already exited, when subprocess.Popen.Terminate calls the Windows built-in "TerminateProcess" function, an "access denied" error will occur. Should I just make it so that this exception is simply ignored or perform some kind of check to see if the process exists beforehand? If the latter, I have been unable to find a way to do so, to my liking at least. The solutions I saw would require code that seems a bit excessive to me. Eric