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 for easier dictionary subclassing
UserList	Wrapper around list objects for easier list subclassing
UserString	Wrapper around string objects for easier string subclassing

 

We don't have the room to cover all of them, but you can find plenty of examples in the official documentation, so here I'll just give a small example...