问题描述
在Python 2(2.7,更准确地说)中,我想以递减计数顺序迭代collections.Counter实例。
In Python 2 (2.7, to be more precise), I want to iterate over a collections.Counter instance in descending count order.
>>> import collections
>>> c = collections.Counter()
>>> c['a'] = 1
>>> c['b'] = 999
>>> c
Counter({'b': 999, 'a': 1})
>>> for x in c:
print x
a
b
在上面的示例,似乎元素按照它们添加到Counter实例的顺序进行迭代。
In the example above, it appears that the elements are iterated in the order they were added to the Counter instance.
我想从最高到最低迭代列表。我看到Counter的字符串表示就是这样,只是想知道是否有推荐的方法来做它。
I'd like to iterate over the list from highest to lowest. I see that the string representation of Counter does this, just wondering if there's a recommended way to do it.
推荐答案
你可以迭代超过 c.most_common()
以获得所需订单的商品。另请参阅。
You can iterate over c.most_common()
to get the items in the desired order. See also the documentation of Counter.most_common()
.
示例:
>>> c = collections.Counter(a=1, b=999)
>>> c.most_common()
[('b', 999), ('a', 1)]
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