自定义Python两个列表映射

Question

我有一个对象ID的映射：

mapping = {'id-1':'id-10', 'id-2':'id-14', 'id-3':'id-19'}

和两个包含对象的列表，id是对象的属性，如object_id1.id = 'id-1'。

list1 = [object_id1, object_id3, object_id4, object_id5]
list2 = [object_id19, object_id11, object_id14, object_id10]

我想要一个列表，将这些相关对象放在一个集合中。比如

​

output = [(object_id1, object_id10), (object_id2, object_id14),(object_id3, object_id19)]

这有可能在一个for循环中完成吗？

Answer 1

不能在单个for循环中完成，但可以在两个(而不是嵌套的)循环中完成：

>>> mapping = {'id-1': 'id-10', 'id-2': 'id-14', 'id-3': 'id-19'}
>>> list1 = [object_id1, object_id3, object_id4, object_id5]
>>> list2 = [object_id19, object_id11, object_id14, object_id10]

构造用于在list2中通过id查找项目的查找字典

>>> lookup_dict = {item.id: item for item in list2}

然后，您可以简单地执行以下操作：

>>> output = [(item, lookup_dict[mapping[item.id]]) for item in list1 if mapping[item.id] in lookup_dict]

Answer 2

编辑:修正了我对这个问题的误解，这部分改编自：Searching a list of objects in Python

假设list1和list2之间没有重复项，并且总是找到匹配项

这可能可以解决这个问题，我还没有测试过，所以你可能会发现一些语法错误：

for item in map:
   xResult = [x for x in list1 if x.id == item or x.id == map[item]][0]
   yResult = [y for y in list2 if y.id == item or y.id == map[item]][0]
   if item == xResult:
       firstTupleItem = xResult
       secondTupleItem = yResult
   else:
       firstTupleItem = yResult
       secondTupleItem = xResult
   tuple = (firstTupleItem,secondTupleItem)
   output.append(tuple)

当然，这可以得到很大的优化或改进，但这可能是一个合理的起点

编辑:Selcuk的答案更理想，但我将继续保持这一点作为参考