download.py 文件源码

def __enter__(self):
        self.bar = progressbar.ProgressBar(
            widgets=[
                progressbar.Percentage(),
                ' ',
                progressbar.Bar(),
                progressbar.FileTransferSpeed(),
                ' ',
                progressbar.ETA(),
            ],
            max_value=self.max_value,
        )
        self.fd = open(self.output_path, 'wb')
        return self