Dealing with nested data

A dictionary can contain another dictionary as the value of a key, and this is a very common way to deal with repeating data structures such as yearly, monthly or weekly data. All the same rules apply when creating or accessing the dictionary.

For example, if you had a dictionary that had a ranking of my cookie consumption by year and type of cookie. It might look like cookies = {'2017': {'chocolate chip': 483, 'peanut butter': 115}, '2016': {'chocolate chip': 9513, 'peanut butter': 6792}}. I could access how many chocolate chip cookies I ate in 2016 using cookies['2016']['chocolate chip'].

When exploring a new dictionary, it can be helpful to use the .keys() method to get an idea of what data might be available within the dictionary. You can also iterate over a dictionary and it will return each key in the dictionary for you to use inside the loop. Here, a dictionary called boy_names has been loaded into your workspace. It consists of all male names in 2013 and 2014.

Print the keys of the boy_names dictionary.
Print the keys of the boy_names dictionary for the year 2013.
Loop over the boy_names dictionary.
- Inside the loop, safely print the year and the third ranked name. Print 'Unknown' if the third ranked name is not found.

Exercise

Dealing with nested data

Instructions