os.nice(increment) Add increment to the process’s “niceness”. Return the new niceness. Availability: Unix.

os.path.splitext(path) Split the pathname path into a pair (root, ext) such that root + ext == path, and ext is empty or begins with a period and contains at most one period. Leading periods on the basename are ignored; splitext('.cshrc') returns ('.cshrc', '').

is_alive() Return whether the process is alive. Roughly, a process object is alive from the moment the start() method returns until the child process terminates.

empty A special class-level marker to specify absence of default values and annotations.

left The directory a.

AbstractEventLoop.is_closed() Returns True if the event loop was closed. New in version 3.4.2.

object.__setstate__(state) Upon unpickling, if the class defines __setstate__(), it is called with the unpickled state. In that case, there is no requirement for the state object to be a dictionary. Otherwise, the pickled state must be a dictionary and its items are assigned to the new instance’s dictionary. Note If __getstate__() returns a false value, the __setstate__() method will not be called upon unpickling.

set_event_loop(loop) Set the event loop for the current context to loop.

os.lchflags(path, flags) Set the flags of path to the numeric flags, like chflags(), but do not follow symbolic links. As of Python 3.3, this is equivalent to os.chflags(path, flags, follow_symlinks=False). Availability: Unix.

os.isatty(fd) Return True if the file descriptor fd is open and connected to a tty(-like) device, else False.