Learn Web Development with Python

The collections module

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

Data type	Description
namedtuple()	Factory function for creating tuple subclasses with named fields
deque	List-like container with fast appends and pops on either end
ChainMap	Dictionary-like class for creating a single view of multiple mappings
Counter	Dictionary subclass for counting hashable objects
OrderedDict	Dictionary subclass that remembers the order entries were added
defaultdict	Dictionary subclass that calls a factory function to supply missing values
UserDict	Wrapper around dictionary objects ...