How to get the first and the last matching occurrence of an array in python?

There is a interview question from AirBNB:

You have a sorted array, and you want get the first index and the last index of the matching occurrence of an element by a function in python. If there is no match, return [-1.-1]. If there is a match, return [first_index,last_index].

This is my newbie solution, can anyone come up with a better one?

By the way, this question is from TechLead DailyInterviewPro.

def solution(array,key):
    start_index = -1
    ending_index = -1
    if key not in array:
        return [start_index,ending_index]
    else:
        for i in range(len(array)):
            if array[i]==key:
                if start_index == -1:
                
                    start_index = i
                    ending_index = i
                else:
                    ending_index = i
                    
        return [start_index,ending_index]        

>Solution :

with one liner, using list.index function you can use

[-1, -1] if key not in array else [arrary.index(key),len(array)-array[::-1].index(key)-1 ]