How do I take an array indicating the indicies of another array and store those values in yet another array?

Question

I am using Python 3.6 in Jupyter Notebooks.

So, I have an array that indicates the indices of another array, for example,

[10, 123, 320, 800] 

would correspond to entry 10, entry 123, and so on. These are the indices of value of interest in another array, around 700 entries long. I need to take these indicated entries and store them in a separate array. I also need to keep all the entries in the same chronological order they were in before I started. Any ideas?

Answer 1

假设索引列表存储为变量i ，主列表存储为变量l ，则可以使用以下列表推导构造一个列表，该列表的值与i的索引指示的l的值相对应：

[l[n] for n in i]