box.py 文件源码

def to_json(self, filename=None,
                encoding="utf-8", errors="strict",
                multiline=False, **json_kwargs):
        """
        Transform the BoxList object into a JSON string.

        :param filename: If provided will save to file
        :param encoding: File encoding
        :param errors: How to handle encoding errors
        :param multiline: Put each item in list onto it's own line
        :param json_kwargs: additional arguments to pass to json.dump(s)
        :return: string of JSON or return of `json.dump`
        """
        if filename and multiline:
            lines = [_to_json(item, filename=False, encoding=encoding,
                              errors=errors, **json_kwargs) for item in self]
            with open(filename, 'w', encoding=encoding, errors=errors) as f:
                f.write("\n".join(lines).decode('utf-8') if
                        sys.version_info < (3, 0) else "\n".join(lines))
        else:
            return _to_json(self.to_list(), filename=filename,
                            encoding=encoding, errors=errors, **json_kwargs)