如何在Python代码中摆脱嵌套的for循环？

I have 1 year of satellite measurements of the electrons (the instrument was measuring every 4 seconds). This array is called 'electrons'. I also have the corresponding times in format datetime.datetime (called 'time'). I want to average electrons array to get a mean value for every minute instead of every 4 seconds. I wanna put them in a new array 'g'. However, when I write the loops, it becomes extremely slow. Is there any way to make it faster? Here is what I do:I have 1 year of satellite measurements of the