Turn Pandas Multi-Index into column

I have a dataframe with 2 index levels:

                             value
    Trial    measurement
        1              0        13
                       1         3
                       2         4
        2              0       NaN
                       1        12
        3              0        34

Which I want to turn into this:

    Trial    measurement       value

        1              0        13
        1              1         3
        1              2         4
        2              0       NaN
        2              1        12
        3              0        34

How can I best do this?

I need this because I want to aggregate the data as instructed here, but I can't select my columns like that if they are in use as indices.

The _resetindex() is a pandas DataFrame method that will transfer index values into the DataFrame as columns. The default setting for the parameter is drop=False (which will keep the index values as columns).

All you have to do add .reset_index(inplace=True) after the name of the DataFrame:

    df.reset_index(inplace=True)

From: stackoverflow.com/q/20110170