pandas官方文档：​​https://pandas.pydata.org/docs/​​

​​python dataframe根据列号取出列​​​​pandas数据框获取行数列数​​​​pandas判断数据框是否相等​​ 添加新列：​​https://www.geeksforgeeks.org/adding-new-column-to-existing-dataframe-in-pandas/​​