What are the differences between a list and a defaultdict in Python?

Can you explain the differences between a list and a defaultdict in Python?

Sure! A list is a built-in data structure that stores an ordered collection of items, while a defaultdict is a subclass of the built-in dict that provides a default value for non-existent keys.

What are some use cases for defaultdict?

Defaultdict is useful when you want to group items or count occurrences without checking if the key exists first. For example, counting words in a sentence.

Can you give me a code example of how to use defaultdict?

Absolutely! Here's a simple example:

from collections import defaultdict

word_count = defaultdict(int)
for word in ['apple', 'banana', 'apple']:
    word_count[word] += 1
print(word_count)

This will output: defaultdict(<class 'int'>, {'apple': 2, 'banana': 1}).

How does list performance compare to defaultdict?

Lists are generally faster for indexing and iteration, while defaultdict can be more efficient for counting or grouping tasks due to its automatic handling of missing keys.