With compound data structures such as our table of isotypes, it can be helpful to have them printed out in a much more readable form. We can do this with the Python Standard Library pretty-printing module called pprint, which contains a function called pprint:

>>> from pprint import pprint as pp

Note that if we didn't bind the pprint function to a different name pp, the function reference would overwrite the module reference, preventing further access to contents of the module:

>>> pp(m)
{
     'B': [10, 11],
     'Be': [7, 9, 10],
     'C': [11, 12, 13, 14],
     'H': [1, 2, 3, 4, 5, 6, 7],
     'He': [3, 4],
     'Li': [6, 7],
     'N': [13, 14, 15]
}

Gives us a much more comprehensible display.

Let's move on from dictionaries and look at a new built-in data structure, the set.