background.py 文件源码

def _process_exists(pid):
    """Check if a process with PID ``pid`` exists.

    :param pid: PID to check
    :type pid: ``int``
    :returns: ``True`` if process exists, else ``False``
    :rtype: ``Boolean``

    """
    try:
        os.kill(pid, 0)
    except OSError:  # not running
        return False
    return True