In addition to Python’s built-in data structures (such as tuples, dicts, and lists), a library module called collections provides data structures with additional features, some of which are specializations of the built-in ones.

Import the module:

import collections

Specialized container datatypes are usually dict subclasses or wrappers around other classes like lists, tuples, etc.

Notable implementations are :

  • the Counter class used for counting hashable objects.
  • defaultdict class used as a faster implementation of a specialised dictionary.
  • namedtuple class used for defining a meaning for every position in a tuple, often useful with databases or CSV files.