使用嵌套字典初始化

import collections
tree = lambda: collections.defaultdict(tree)
some_dict = tree()
some_dict['colours']['favourite'] = "yellow"

Counter 计数

from collections import Counter

colours = (
    ('Yasoob', 'Yellow'),
    ('Ali', 'Blue'),
    ('Arham', 'Green'),
    ('Ali', 'Black'),
    ('Yasoob', 'Red'),
    ('Ahmed', 'Silver'),
)

favs = Counter(name for name, colour in colours)
print(favs)

deque

NameTuple

nametuple 把元组变成一个针对简单任务的容器。你不必使用整数索引来访问一个namedtuples的数据。你可以像字典(dict)一样访问namedtuples，但namedtuples是不可变的。

from collections import namedtuple

Animal = namedtuple('Animal', 'name age type')
perry = Animal(name='perry', age=31, type='cat')
print(perry)
## Output: Animal(name='perry', age=31, type='cat')
print(perry.name)
## Output: 'perry'

# 将一个命名元组转换为字典
print(perry._asdict())
## Output: OrderedDict([('name', 'Perry'), ('age', 31'), ...

Enum

from collections import namedtuple
from enum import Enum

class Species(Enum):
    cat = 1
    dog = 2
    horse = 3
    aardvark = 4
    butterfly = 5
    owl = 6
    platypus = 7
    dragon = 8
    unicorn = 9
    # 依次类推

		# 但我们并不想关心同一物种的年龄，所以我们可以使用一个别名
    kitten = 1  # (译者注：幼小的猫咪)
    puppy = 2   # (译者注：幼小的狗狗)

Animal = namedtuple('Animal', 'name age type')
perry = Animal(name="Perry", age=31, type=Species.cat)
drogon = Animal(name="Drogon", age=4, type=Species.dragon)
tom = Animal(name="Tom", age=75, type=Species.cat)
charlie = Animal(name="Charlie", age=2, type=Species.kitten)