计算字典的键,python

从问题的顶部来看,您似乎在试图找到列表中每对元素的总和,并计算每个总和出现的次数。

from itertools import combinations
from collections import Counter

number_list = [1, 2, 3, 4, 5]
sum_counter = Counter(map(sum, combinations(number_list, 2)))

print(sum_counter)
# {3: 1, 4: 1, 5: 2, 6: 2, 7: 2, 8: 1, 9: 1}

通过改变参数,可以很容易地将其推广到计算三元组、四元组等的总和 2 combinations .

count=1
for n1 in number_list:
    for n2 in number_list:

        sum=n1+n2

        if (n2,n1) not in pair_dict and n1!=n2:
            pair_dict[(n1,n2)]=sum
            sum_dict[sum]=(n1,n2)
            if sum_dict[sum]==(n2,n1):
                count_dict[sum]=count
            else:
                count+=1
                count_dict[sum]+=count
        else:
            pass