Open files with the appropriate application

def open(self, fnames=None):
        """Open files with the appropriate application"""
        if fnames is None:
            fnames = self.get_selected_filenames()
        for fname in fnames:
            if osp.isfile(fname) and encoding.is_text_file(fname):
                self.parent_widget.sig_open_file.emit(fname)
            else:
                self.open_outside_spyder([fname])