python - 按类的属性分组和计数

Question

我有一个结果类如下

class Result:
    cluster = -1;
    label = -1;

簇和标签都可以有 0-9 之间的值，我想做的是计算簇中标签的数量。目前我正在使用以下代码进行计数，但这不是一个优雅的解决方案。 resultList 是 Result 对象的列表。

countZero = 0;
countOne = 0;
countTwo = 0;
countThree = 0;
countFour = 0;
countFive = 0;
countSix = 0;
countSeven = 0;
countEight = 0;
countNine = 0;

    for i in range(len(resultList)):
        if resultList[i].cluster == 0:
            if resultList[i].label == 0:
                countZero = countZero + 1
            if resultList[i].label == 1:
                countOne = countOne + 1
            if resultList[i].label == 2:
                countTwo = countTwo + 1
            if resultList[i].label == 3:
                countThree = countThree + 1
            if resultList[i].label == 4:
                countFour = countFour + 1
            if resultList[i].label == 5:
                countFive = countFive + 1
            if resultList[i].label == 6:
                countSix = countSix + 1
            if resultList[i].label == 7:
                countSeven = countSeven + 1
            if resultList[i].label == 8:
                countEight = countEight + 1
            if resultList[i].label == 9:
                countNine = countNine + 1

    print(countZero) # 
    print(countOne) # 
    print(countTwo) # 
    print(countThree) #
    print(countFour) # 
    print(countFive) # 
    print(countSix) # 
    print(countSeven) # 
    print(countEight) # 
    print(countNine) #

如有任何关于寻找更好解决方案的建议或指导，我们将不胜感激。

Answer 1

Counter 函数返回一个字典，其中包含每个标签的计数。以这种方式将其用于集群 0:

from collections import Counter

Counter(resultList[resultList['cluster']==0]]['label'])