>>> [i for i,v in enumerate(a) if v > 4] [4, 5, 6, 7, 8] #enumerate returns the index and value of each item in an array. #So if the value v is greater than 4, include the index i in the new array.
Here is what the above code is Doing:
1. Create a new list
2. For each item in the array a, get the index and value
3. If the value is greater than 4, include the index in the new list