计数数组中的列表成员对

Question

假设我有一个包含以下列表的数组:

data = [['a', 'b', 'c'],['a', 'b'],['c']]

根据它们在列表中的数量来计算每一对出现的最佳解决方案是什么?

。结果应为:

member_one_is  member_two_is  COUNT
a              b              2
a              c              1
b              c              1

Answer 1

使用collections.Counter和itertools.combinations的一种方法:

from collections import Counter
from itertools import combinations
import pandas as pd
data = [['a', 'b', 'c'], ['a', 'b'], ['c']]
# get the counts using collections Counter and the combinations using combinations
# make sure each sub-list is sorted with sorted
counts = Counter(combination for lst in map(sorted, data) for combination in combinations(lst, 2))
# create the DataFrame
df = pd.DataFrame(data=[[*k, v] for k, v in counts.items()], columns=["member_one_is", "member_two_is", "COUNT"])
print(df)

member_one_is member_two_is  COUNT
0             a             b      2
1             a             c      1
2             b             c      1

注意，如果列表是排序的，您可以跳过map(sorted, data)并直接迭代data。