cached_file.py 文件源码

def flags(self):
        '''
        Adapted from http://hg.python.org/cpython/file/84cf25da86e8/Lib/_pyio.py#l154

        See also open(2) which explains the modes

        os.O_BINARY and os.O_TEXT are only available on Windows.
        '''
        return (
            ((self.reading and not self.updating) and os.O_RDONLY or 0) |
            ((self.writing and not self.updating) and os.O_WRONLY or 0) |
            ((self.creating_exclusively and not self.updating) and os.O_EXCL or 0) |
            (self.updating and os.O_RDWR or 0) |
            (self.appending and os.O_APPEND or 0) |
            ((self.writing or self.creating_exclusively) and os.O_CREAT or 0) |
            (self.writing and os.O_TRUNC or 0) |
            ((self.binary and hasattr(os, 'O_BINARY')) and os.O_BINARY or 0) |
            ((self.text and hasattr(os, 'O_TEXT')) and os.O_TEXT or 0)
        )