test_file.py 文件源码

def valid_io_modes(self, *a, **kw):
        modes = set()
        t = LocalTarget(is_tmp=True)
        t.open('w').close()
        for mode in self.theoretical_io_modes(*a, **kw):
            try:
                io.FileIO(t.path, mode).close()
            except ValueError:
                pass
            except IOError as err:
                if err.errno == EEXIST:
                    modes.add(mode)
                else:
                    raise
            else:
                modes.add(mode)
        return modes