Using defaultdict

We’ve seen how to use the setdefault method to set a default value if a key doesn’t exist, but this can get a bit monotonous if we need to set a default value every time we look up a value. Let’s have a look at an example to better understand this concept.

Example: Count letters

For example, if we’re writing code that counts the number of times a letter occurs in a given sentence, we could do the following: