How do I use default keys in Python dictionaries?

Can you explain how to use default keys in Python dictionaries?

Sure! In Python, you can use the defaultdict from the collections module to create a dictionary that provides default values for nonexistent keys.

What is the difference between a regular dictionary and a defaultdict?

A regular dictionary raises a KeyError if you try to access a key that doesn't exist, while a defaultdict returns a default value instead.

Can you give me an example of how to implement defaultdict?

Of course! Here's a simple example:

from collections import defaultdict

d = defaultdict(int)

d['a'] += 1
print(d['a'])  # Output: 1
print(d['b'])  # Output: 0 (default value)