选择数据透视表列

Question

I have a pivot table like this;

                     amount
product year-month         
5       2015-03-01    408.0
        2015-04-01   6081.0
        2015-05-01  10915.0
        2015-06-01  12202.0
        2015-07-01  13342.0
        2015-08-01  18786.0
        2015-09-01   9491.0
        2015-10-01   6014.0
                ...

I can't select index columns. How can I select column 'year-month' or 'amount'?

year-month         
2015-03-01   
2015-04-01  
2015-05-01  
2015-06-01
...  

Edit

This doesn't work;

pivot_df['year-month']

Answer 1

One command which is very useful, especially after a pivot table command, is to reset the index:

pivot_df.reset_index(inplace=True)

You can also set a specific column to be an index:

pivot_df.set_index('year-month', inplace=True)