How does dataframe calculate the average value of each row as another column

You can use the following code to calculate .

df['Col_sum'] = df.apply(lambda x: x.sum(), axis=1)

In addition, how to calculate the average value of each column as another row

df.loc['Row_sum'] = df.apply(lambda x: x.sum())

Of course , This method can be used to calculate variance and other statistical data , For example, to calculate variance, just replace it with x.std() That's it .