How do I use dictionaries in Python's collections module?

How do I use dictionaries in Python's collections module?

In Python, the collections module provides a specialized dictionary called defaultdict. It allows you to set default values for keys that don't exist.

Can you give me an example of how defaultdict works?

Sure! Here's a simple example:

from collections import defaultdict

default_dict = defaultdict(int)

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

What other types of dictionaries are available in the collections module?

Besides defaultdict, the collections module also includes OrderedDict, which maintains the order of keys, and Counter, which counts hashable objects.

How does OrderedDict differ from a regular dictionary?

OrderedDict remembers the order in which items were added, while regular dictionaries (as of Python 3.7) maintain insertion order as well, but OrderedDict has additional methods for reordering.