tarfile.py 文件源码

def xzopen(cls, name, mode="r", fileobj=None, preset=None, **kwargs):
        """Open lzma compressed tar archive name for reading or writing.
           Appending is not allowed.
        """
        if mode not in ("r", "w", "x"):
            raise ValueError("mode must be 'r', 'w' or 'x'")

        try:
            import lzma
        except ImportError:
            raise CompressionError("lzma module is not available")

        fileobj = lzma.LZMAFile(fileobj or name, mode, preset=preset)

        try:
            t = cls.taropen(name, mode, fileobj, **kwargs)
        except (lzma.LZMAError, EOFError):
            fileobj.close()
            if mode == 'r':
                raise ReadError("not an lzma file")
            raise
        except:
            fileobj.close()
            raise
        t._extfileobj = False
        return t

    # All *open() methods are registered here.