Metodi dei dizionari

Introduzione

keys(), values(), items()

d = {'a': 1, 'b': 2}
print(list(d.keys()))
print(list(d.values()))
print(list(d.items()))

update()

d = {'a': 1}
d.update({'b': 2, 'a': 99})
print(d)

pop() con valore predefinito

d = {'a': 1, 'b': 2}
val = d.pop('a')
print(val, d)

popitem()

d = {'a': 1, 'b': 2}
print(d.popitem())
print(d)

setdefault()

d = {}
d.setdefault('count', 0)
d['count'] += 1
print(d)

Unire con | (Python 3.9+)

d1 = {'a': 1}
d2 = {'b': 2}
print(d1 | d2)

copy() e deepcopy()

import copy
d = {'a': [1,2]}
deep = copy.deepcopy(d)
deep['a'].append(3)
print(d, deep)

Counter da collections

from collections import Counter
c = Counter('banana')
print(c)

defaultdict

from collections import defaultdict
d = defaultdict(list)
d['a'].append(1)
print(d)

OrderedDict (nota legacy)

from collections import OrderedDict
od = OrderedDict({'a':1,'b':2})
od.move_to_end('a')
print(list(od))

Verifica rapida

Riepilogo

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