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python-day20--collections模块

1.namedtuple: 生成可以使用名字来访问元素内容的tuple

技术分享
>>> from collections import namedtuple
>>> Point = namedtuple(Point, [x, y])
>>> p = Point(1, 2)
>>> p.x
>>> p.y
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2.OrderedDict: 有序字典

>>> from collections import OrderedDict
>>> d = dict([(a, 1), (b, 2), (c, 3)])
>>> d # dict的Key是无序的
{a: 1, c: 3, b: 2}
>>> od = OrderedDict([(a, 1), (b, 2), (c, 3)])
>>> od # OrderedDict的Key是有序的
OrderedDict([(a, 1), (b, 2), (c, 3)])

3.defaultdict: 带有默认值的字典

技术分享
from collections import defaultdict

values = [11, 22, 33,44,55,66,77,88,99,90]

my_dict = defaultdict(list)

for value in  values:
    if value>66:
        my_dict[k1].append(value)
    else:
        my_dict[k2].append(value)

defaultdict字典解决方法
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python-day20--collections模块