collections.namedtuple#

Shortcut For Simple Data-Holding Classes#

  • Much writing for a simple data holder

    class Person:
    def __init__(self, firstname, lastname):
        self.firstname = firstname
        self.lastname = lastname

person = Person('Joerg', 'Faschingbauer')
print(person.firstname, person.lastname)

    Joerg Faschingbauer

  • Written shorter (and with much more features - but read on)

    from collections import namedtuple
Person = namedtuple('Person', ('firstname', 'lastname'))

person = Person('Joerg', 'Faschingbauer')
print(person.firstname, person.lastname)

    Joerg Faschingbauer

Constructing From Iterable: _make()#

  • Data-holding classes are popular with tabular data (CSV, databases, …)

  • Rows are iterable

  • ⟶ someclass._make()

  • Example: rows read from a CSV file

    persons_from_csv = [
    ['Joerg', 'Faschingbauer'],
    ['Caro', 'Faschingbauer'],
]

  • Turning each into a Person object

    for person in map(Person._make, persons_from_csv):
    print(person.firstname, person.lastname)

    Joerg Faschingbauer
Caro Faschingbauer

Convert To dict: _asdict()#

person = Person('Joerg', 'Faschingbauer')
person_dict = person._asdict()
person_dict

{'firstname': 'Joerg', 'lastname': 'Faschingbauer'}