Follows a couple of minor concerns.

- What about Solaris' /dev/poll?

- I'm not sure why in case of EINTR you retry with a different timeout; can't you just return []? 

- this is probably because I'm paranoid about performances but given that select() method will be called repeatedly I would not use a decorator. Also, similarly to what has been done elsewhere in the stdlib, for "critical" parts I would recommend localizing variable access in order to minimize overhead as in:

    def select(self, timeout=None):
        ... 
        key_from_fd = self._key_from_fd
        ready_append = ready.append
        for fd in r | w:
            ...
            key = key_from_fd(fd)
            if key:
                ready_append((key, events & key.events))