How can I use defaultdict in Python for grouping data?

How can I use defaultdict in Python for grouping data?

You can use defaultdict from the collections module to group data easily. It allows you to set a default value for non-existent keys.

Can you show me a code example?

Sure! Here's a simple example:

from collections import defaultdict

data = [('a', 1), ('b', 2), ('a', 3)]

grouped = defaultdict(list)

for key, value in data:
    grouped[key].append(value)

print(grouped)

This will group the values by their keys.

What if I want to group by a different criterion?

You can modify the key in the loop to group by any criterion you want. Just change the first element of the tuple in the data.