如果我在堆中推出列表元素，将使用什么堆订购属性？
假设我创建一个堆，并在堆内推出一些列表元素，如下所示：
from heapq import heapify,heappop,heappush
pq = []
heapify(pq)
heappush(pq,[4,0,1])
heappush(pq,[7,1,3])
heappush(pq,[2,4,2])
heappop（）操作返回值将如何？ 就我而言，我希望列表中的第一个元素在Min Heap Ordering属性中使用。我该如何实现？
Suppose I create a heap and push some list elements inside the heap as follows:
from heapq import heapify,heappop,heappush
pq = []
heapify(pq)
heappush(pq,[4,0,1])
heappush(pq,[7,1,3])
heappush(pq,[2,4,2])
How will the heappop() operation return values?
In my case, I want the first element of the list to be used in min heap ordering property. How can I achieve that?
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那将会发生。将比较您作为参数所传递的项目
heappush。在Python中，将其第一个成员比较列表，如果是领带，则由其第二会员等。因此，例如[2,4,2]小于[2,8,1]。这是一种与列表和元素相关的行为，并非针对hapq，但hapq依赖于此。在您的示例中，当您继续从堆中弹出元素时，如下：
您会以分类顺序输出：
备注
，因为您不希望堆上的元素被突变（因为那可能会破坏适当的堆订单），您应该更好地使用元组而不是 lists ：
That is what will happen. The items you pass as argument in
heappushwill be compared. In Python, lists are compared by their first member, and if that is a tie, by their second member, ...etc. So for example[2,4,2]is less than[2,8,1]. This is a behaviour that is tied to lists and tuples, and is not specific forheapq, butheapqrelies on it.In your example, when you continue to pop the elements from the heap, like this:
You'll get them output in sorted order:
Remark
As you don't want elements on the heap to be mutated (as that could break there proper heap order), you should better use tuples and not lists: