如果另一个列表中的元素之差小于某个值，如何对列表中的元素求和

def sum_elements_if_difference_less_than(list1, list2, threshold):
    total_sum = 0
    for a, b in zip(list1, list2):
        if abs(a - b) < threshold:
            total_sum += a + b
    return total_sum

# 示例使用
list1 = [1, 2, 3, 4]
list2 = [1.5, 2.5, 3.5, 4.5]
threshold = 1.0

result = sum_elements_if_difference_less_than(list1, list2, threshold)
print("Sum of elements where difference is less than threshold:", result)

from itertools import zip_longest

def sum_elements_if_difference_less_than(list1, list2, threshold):
    total_sum = 0
    for a, b in zip_longest(list1, list2, fillvalue=None):
        if a is not None and b is not None and abs(a - b) < threshold:
            total_sum += a + b
    return total_sum