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python之在 python 中的循环中编写循环的更简洁的方法

2025年05月04日16birdshome

我有一个对象列表,这些对象是我代码中的特定类,

[object1, object2, object3, object4, object5, object6] 

即这个类有两个属性:class.score和class.id

我可能有具有相同 ID 的对象。例如:

[object1.id, object2.id, object3.id, object4.id, object5.id, object6.id] = [1, 2, 3, 4, 2, 3] 

但分数不同。例如:

[object1.score, object2.score, object3.score, object4.score, object5.score, 
object6.score] = [0.25, 0.55, 0.6, 0.4, 0.30, .33] 

我想要做的是让这个对象在 id-wise 上没有重复的列表,但是 添加分数。因此对于前面的示例,输出将是:

[object1.id, object2.id, object3.id, object4.id] = [1, 2, 3, 4] 
[object1.score, object2.score, object3.score, object4.score] = [.25, .85, .93, .4] 

我已经设法用两个 for 循环做到了这一点:

k = 1 
    for object in list_of_objects: 
        j = 1 
        for object2 in list_of_objects: 
            if object.id == object2.id and j > k: 
                object.score = object.score + object2.score 
                list_of_objects.remove(object2) 
            j += 1 
        k += 1 

但我希望以一种更像 python 的方式来实现它:

newlist[:] = [ x for x in list_of_objects if certain_condition(x)] 

谢谢。

请您参考如下方法:

itertools.groupby 正是为这种情况而制作的 https://docs.python.org/2/library/itertools.html#itertools.groupby

from itertools import groupby 
# object.id is our key: 
keyfunc = lambda obj: obj.id 
list_of_objects = sorted(list_of_objects, key=keyfunc) 
 
scores = [sum(score_list) for id, score_list in groupby(list_of_objects, keyfunc)] 
ids = [id for id, score_list in groupby(list_of_objects, keyfunc)]