collections.namedtuple function is a factory that produces subclasses of tuple enhanced with field names and a class name.
Instances of a class that you build with
namedtuple take exactly the same amount of memory as tuples because the field names are stored in the class. They use less memory than a regular object because they do store attributes in a per-instance
Following example defines named tuple to hold information about a city
>>> from collections import namedtuple >>> City = namedtuple('City', 'name country population coordinates') >>> vn = City('Vinnytsia', 'UA', 369.860, (49.233333, 28.483333)) >>> vn City(name='Vinnytsia', country='UA', population=369.860, coordinates=(49.233333, 28.483333)) >>> vn.population 369.860 >>> vn.coordinates (49.233333, 28.483333) >>> vn 369.860
Or let's define a point
>>> Point = namedtuple('Point', ['x', 'y']) >>> pt1 = Point(2, 7) >>> pt.x 2
Two parameters are required to create a named tuple: a class name and a list of field names, which can be given as an iterable of strings or as a single space-delimited string.
Data must be passed as positional arguments to the constructor (in contrast, the tuple constructor takes a single iterable). You can't set attributes of a
namedtuple, just like you can't change members of a tuple. You need to set attributes when you instantiate your
You can access the fields by name or position.