报错：
Aw, snap! We don't have an account for ''. Want to try again? You can authenticate with your email address or username. Sign in is not case sensitive.
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PlotlyError: Because you didn't supply a 'file_id' in the call, we're assuming you're trying to snag a figure from a url. You supplied the url, '', we expected it to start with 'https://plot.ly'.
Run help on this function for more information.
解决办法:在https://plot.ly/注册账户，然后在plotly的credentials文件中设置用户名和API_key，具体方法参见：https://plot.ly/python/getting-started/