如何用python编写一个函数来对给定的一组数字进行求和,而不是用python本身?

其他答案忽略了同一个数字存在重复的可能性:

def sum_neighbours(li): ## Renamed list to li as list is already a python keyword so shouldn't be used as you may accidentally shadow it and have problems
    return [sum(li) - (li.count(num) * num) for num in li]

如果性能是一个关键因素:

def sum_neighbours(li):
    s = sum(li) ## Precompute the sum so that it doesn't need to be recalculated in every iteration
    return [s - (li.count(num) * num) for num in li]

如果重复项不影响您的金额:

    return [sum(li) - num for num in li]

另外,如果您的输入列表总是与[1,2,3,…,n]相似,那么可以通过 s = (s * (s + 1)) / 2 因为这样可以省去程序添加列表中每个数字的麻烦。

也许更像蟒蛇:

 def sum_neighbors(_list):
     s = sum(_list)
     return [s - item for item in _list]

或者,如果你敢:

 def sum_neighbors(_list):
     s = sum(_list)
     return list(map(operator.sub, itertools.repeat(s), _list))

要处理重复项:

def sum_neighbors(_list):
    counts = collections.Counter(_list)
    s = sum(_list)
    return [s - counts[item] * item for item in _list]

提示:我已重命名 list 到 _list 这样你就不会在建筑上留下阴影 列表 键入。

我认为最好用这个:

a = [1,2,3,4]
result = [sum(a)-i for i in a]

输出:

[9, 8, 7, 6]

def add_func(lst):
      return list(sum(lst)-i for i in lst))

print(add_func([1,2,3,4]))