Standard Library

Python collections Module

Python Specialized Containers

Python collections module offers Counter and deque containers.

Introduction to Python collections Module

The collections module in Python provides specialized container datatypes that offer alternatives to Python's built-in containers like lists, dicts, sets, and tuples. This module helps developers to write more efficient and readable code, especially in scenarios that require maintaining order, counting elements, or creating specialized data structures.

Using the Counter Class

The Counter class is a subclass of the dictionary object in Python. It is used to count hashable objects and is part of the collections module. Counter is particularly useful for tallying elements in an iterable or finding the most common elements in a sequence.

Here is a basic example of how to use Counter:

The Counter object can also be used to find the n most common elements:

Using the deque Class

The deque class (pronounced "deck") is a double-ended queue, which means you can append and pop elements from either end with O(1) performance. This makes deque a great choice for implementing queue and stack-like structures.

Here's how you can use a deque:

The deque also supports removing elements from both ends:

When to Use collections Module

The collections module should be used when you need efficient data storage and retrieval, particularly when dealing with large datasets. Use Counter when counting elements or determining frequency, and deque for fast appends and pops from both ends of a sequence.

Explore other classes in the collections module like OrderedDict, defaultdict, and namedtuple for more specialized data storage solutions.

Standard Library

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