https://matplotlib.org/examples/index.html
https://matplotlib.org/gallery.html
http://pandas.pydata.org/pandas-docs/stable/reference/index.html
http://www.runoob.com/numpy/numpy-tutorial.html
https://www.yiibai.com/pandas/python_pandas_series.html
http://www.runoob.com/w3cnote/matplotlib-tutorial.html
https://www.w3cschool.cn/r/
https://www.pytorchtutorial.com/