A dictionary is similar to a list, but you access values by looking up a key instead of an index. A key can be any string or number. The syntax to define a dictionary is:

>>> {}

{}

This shows that you just created an empty dictionary. Hurray!

Now, try writing the following command:

>>> django_dolls = {'Dottie' : 15, 'Lottie' : 305, 'EmmyLou' : 17}

Don't be surprised with the weird names. Go to the link: http://hubpages.com/hub/50-Doll-Names to look for more cute doll names. :P Just Kidding (You should do this if and only if you have a lot of time).

- Do you need to associate values with keys, so you can look them up efficiently (by key) later on? Use a dictionary.

Dictionaries are mutable like "lists" meaning that they can be changed after they are created. You can add new key/value pairs to the dictionary after it is created, like:

>>> django_dolls['Jilly'] = 67

Like the lists, using len() method on the dictionaries, returns the number of key-value pairs in the dictionary. Go ahead and type in the command:

>>> len(django_dolls)

4

As you can see from the output, the key-value pair corresponding to 'Dottie' key has been deleted.

Apart from this, you can also change a value associated with an already created key in the dictionary. Type:

>>> django_dolls['Jilly'] = 100

>>> django_dolls

{'Jilly': 100, 'EmmyLou': 17, 'Lottie': 305}