The collections module

When Python general purpose built-in containers (tuple, list, set, and dict) aren't enough, we can find specialized container data types in the collections module. They are:

Data type

Description

namedtuple()

A factory function for creating tuple subclasses with named fields

deque

A list-like container with fast appends and pops on either end

ChainMap

A dict-like class for creating a single view of multiple mappings

Counter

A dict subclass for counting hashable objects

OrderedDict

A dict subclass that remembers the order entries were added

defaultdict

A dict subclass that calls a factory function to supply missing values

UserDict

A wrapper around dictionary objects for easier dict subclassing

UserList

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