'returns evince-related settings as a tuple
(python, sync_wait)'

def _get_settings(self):

    linux_settings = get_setting('linux', {})
    python = linux_settings.get('python')
    if ((python is None) or (python == '')):
        python = linux_settings.get('python2')
    if ((python is None) or (python == '')):
        if (self.PYTHON is not None):
            python = self.PYTHON
        else:
            try:
                check_call(['python', '-c', 'import    dbus'], use_texpath=False)
                python = 'python'
            except:
                try:
                    check_call(['python3', '-c', 'import    dbus'], use_texpath=False)
                    python = 'python3'
                except:
                    sublime.error_message('Cannot    find    a    valid    Python    interpreter.\n                                                                                                                Please    set    the    python    setting    in    your    LaTeXTools\n                                                                                                                settings.'.strip())
                    raise Exception('Cannot    find    a    valid    interpreter')
            self.PYTHON = python
    return (python, (linux_settings.get('sync_wait') or 1.0))
