从计数器列表更新计数器而不循环? [英] Update a counter from a list of counters without a loop?

问题描述

我有一个柜台清单:

from collections import Counter
counters = [
    Counter({"coach": 1, "says": 1, "play": 1, "basketball": 1}),
    Counter({"i": 2, "said": 1, "hate": 1, "basketball": 1}),
    Counter({"he": 1, "said": 1, "play": 1, "basketball": 1}),
]

我可以使用如下所示的循环来组合它们，但我想避免循环.

I can combine them using a loop as shown below, but I'd like to avoid the loop.

all_ct = Counter()
for ct in counters:
    all_ct.update(ct)

使用 reduce 会出现错误:

all_ct = Counter()
reduce(all_ct.update, counters) 
>>> TypeError: update() takes from 1 to 2 positional arguments but 3 were given

有没有一种方法可以在不使用循环的情况下将计数器合并为一个计数器?

Is there a way to combine the counters into a single counter without using a loop?

推荐答案

您需要将update()替换为reduce可以使用的形式:

You need to replace update() with a form that reduce can use:

def static_update(x, y):
    x.update(y)
    return x

all_ct = Counter()
functools.reduce(static_update, counters)

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