在未完全排序的列表中查找最接近值的项目的索引
问题描述：
例如，我的列表是:
[25.75443, 26.7803, 25.79099, 24.17642, 24.3526, 22.79056, 20.84866, 19.49222, 18.38086, 18.0358, 16.57819, 15.71255, 14.79059, 13.64154, 13.09409, 12.18347, 11.33447, 10.32184, 9.544922, 8.813385, 8.181152, 6.983734, 6.048035, 5.505096, 4.65799]
，并且我正在寻找最接近11.5的值的索引.我尝试了其他方法，例如二进制搜索和bisect_left，但是它们不起作用.
and I'm looking for the index of the value closest to 11.5. I've tried other methods such as binary search and bisect_left but they don't work.
我无法对该数组进行排序，因为该值的索引将用于类似的数组上以获取该索引处的值.
I cannot sort this array, because the index of the value will be used on a similar array to fetch the value at that index.
答
尝试以下操作:
min(range(len(a)), key=lambda i: abs(a[i]-11.5))
例如:
>>> a = [25.75443, 26.7803, 25.79099, 24.17642, 24.3526, 22.79056, 20.84866, 19.49222, 18.38086, 18.0358, 16.57819, 15.71255, 14.79059, 13.64154, 13.09409, 12.18347, 11.33447, 10.32184, 9.544922, 8.813385, 8.181152, 6.983734, 6.048035, 5.505096, 4.65799]
>>> min(range(len(a)), key=lambda i: abs(a[i]-11.5))
16
或者获取索引和值:
>>> min(enumerate(a), key=lambda x: abs(x[1]-11.5))
(16, 11.33447)