New submission from Georg Brandl: -------- Original-Nachricht -------- Betreff: [docs] socket.fileno() documentation Datum: Thu, 10 Oct 2013 19:27:35 +0200 Von: Vlado Potisk <vlado@poti.sk> An: docs@python.org I might be wrong but in my opinion the socket library documentation is not clear enough regarding the behaviour of the fileno() method in a case of a failure. In the Python 3.2 socket library documentation there is: ---- exception socket.error A subclass of IOError, this exception is raised for socket-related errors. ----- socket.close() Close the socket. All future operations on the socket object will fail. ---- socket.fileno() Return the socket’s file descriptor (a small integer). ---- Based on the information quoted above, I wrote a test if a socket is active or if it has been closed already: try: sock.fileno() except socket.error: return False return True But is doesn't work. I have found out that fileno() returns -1 on a closed socket. Replacing fileno() with e.g. getsockname() fixes the code. It looks like a fileno's failure - unlike to getsockname's failure - is not expressed by raising an exception, but by returning -1. However this seems to be not documented and that's why I'm unsure if I may rely on this. ---------- assignee: docs@python components: Documentation messages: 199592 nosy: docs@python, georg.brandl priority: normal severity: normal status: open title: socket.fileno() documentation _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue19234> _______________________________________