如何计算与collection.Counter（）在python中的共同？ [英] How to count co-ocurrences with collections.Counter() in python?

问题描述

我了解了 collections.Counter（）类最近，因为它是一个整洁（和快速??）的方式来计数的东西，我开始使用它。

I learned about the collections.Counter() class recently and, as it's a neat (and fast??) way to count stuff, I started using it.

但我最近检测到我的程序的一个错误，因为当我尝试用元组更新计数时，它实际上将其视为序列， >更新元组中每个项目的计数，而不是计数我插入的特定元组的次数。

But I detected a bug on my program recently due to the fact that when I try to update the count with a tuple, it actually treats it as a sequence and updates the count for each item in the tuple instead of counting how many times I inserted that particular tuple.

，如果你运行：

import collections
counter = collections.Counter()
counter.update(('user1', 'loggedin'))
counter.update(('user2', 'compiled'))
counter.update(('user1', 'compiled'))

print counter

您将获得：

Counter({'compiled': 2, 'user1': 2, 'loggedin': 1, 'user2': 1})

。有没有办法用Counter（）计数元组？我可以连接字符串，但这是...丑陋。我可以使用命名元组吗？实现我自己的非常简单的字典计数器？不知道最好的。

as a result. Is there a way to count tuples with the Counter()? I could concatenate the strings but this is... ugly. Could I use named tuples? Implement my own very simple dictionary counter? Don't know what's best.

推荐答案

当然：你只需要添加一个间接级别，即pass .update 一个以元组为元素的容器。

Sure: you simply have to add one level of indirection, namely pass .update a container with the tuple as an element.

>>> import collections
>>> counter = collections.Counter()
>>> counter.update((('user1', 'loggedin'),))
>>> counter.update((('user2', 'compiled'),))
>>> counter.update((('user1', 'compiled'),))
>>> counter.update((('user1', 'compiled'),))
>>> counter
Counter({('user1', 'compiled'): 2, ('user1', 'loggedin'): 1, ('user2', 'compiled'): 1})

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