Restoring the index order

Continuing from the previous exercise, you will now use .swaplevel(0, 1) to flip the index levels. Note they won't be sorted. To sort them, you will have to follow up with a .sort_index(). You will then obtain the original DataFrame. Note that an unsorted index leads to slicing failures.

To begin, print both users and bycity in the IPython Shell. The goal here is to convert bycity back to something that looks like users.

Define a DataFrame newusers with the 'city' level stacked back into the index of bycity.
Swap the levels of the index of newusers.
Print newusers and verify that the index is not sorted. This has been done for you.
Sort the index of newusers.
Print newusers and verify that the index is now sorted. This has been done for you.
Assert that newusers equals users. This has been done for you, so hit 'Submit Answer' to see the result.

Exercise

Restoring the index order

Instructions