Question

我在下面有这个查询：

high_results = list(
    high_structures.values_list('bldg_name', 'bldg_type').annotate(count=Count('bldg_name')))
high_results.insert(0, 3)

medium_results = list(
    medium_structures.values_list('bldg_name', 'bldg_type').annotate(count=Count('bldg_name')))
medium_results.insert(0, 2)

low_results = list(low_structures.values_list('bldg_name', 'bldg_type').annotate(count=Count('bldg_name')))
low_results.insert(0, 1)

我想在列表中插入一个项目，但问题是，结果不对。

[3, ["Unknown", "Residential", 128], 2, ["Unknown", "Residential", 243], 1, ["Rural Health Center", "Other Government Offices", 1], ["Unknown", "Residential", 384], ["Katugasan Multi-Purpose Gym", "Sport Center/Gymnasium/Covered Court", 1], ["Katugasan Elementary School", "School", 5]]

它没有括在括号中，也没有分开。我该如何解决？输出应该是这样的：

[ [3,"Unknown", "Residential", 128],  [2,"Unknown", "Residential", 243], [ 1,"Rural Health Center", "Other Government Offices", 1],...]

输出：

# Combine all of the structures into a unified response
results = list(chain(high_results, medium_results, low_results))

Answer 1

您似乎将high_results作为列表中的列表。比较

>>> high_results = [["Unknown", "Residential", 128]]
>>> high_results.insert(0, 3)
>>> high_results
[3, ['Unknown', 'Residential', 128]]

与

>>> high_results = [["Unknown", "Residential", 128]]
>>> high_results[0].insert(0, 3)
>>> high_results
[[3, 'Unknown', 'Residential', 128]]

如果high_results有多个元素，并且您希望将3添加到每个元素

high_results = [[3] + x for x in high_results]

同样适用于其他人

Answer 2

您似乎希望将此结果添加到查询中的每个结果集。这最好用列表理解来完成：

high_results = [(3,) + row for row in high_structures.values_list('bldg_name', 'bldg_type').annotate(count=Count('bldg_name'))]
medium_results =  [(2,) + row for row in medium_structures.values_list('bldg_name', 'bldg_type').annotate(count=Count('bldg_name'))]
low_results = [(1,) + row for row in low_structures.values_list('bldg_name', 'bldg_type').annotate(count=Count('bldg_name'))]

(3,) +前缀比high_results.insert(0, 3)调用更容易理解，这也需要您转换每个嵌套元组，然后在循环中应用list.insert()调用。

您可以将这些列表连接在一起，而不是在此处使用chain()：

output = high_results + medium_results + low_results

在python中的列表中插入项目

2 个答案: