Calculating time elapsed for each datapoint (Python, Excel, PowerQuery)

Question

Help needed I am a beginner in data analytics. I have a dataset of a measuring device that measures weight(in kg) every minute.

E.g. dataset

Value         time
150kg      00:01:00
150kg      00:02:02
150kg      00:03:01
700kg      00:04:04
700kg      00:05:05
1100kg     00:06:07
1100kg     00:07:01

I need to calculate the total time elapsed when the weight was 150kg until it was 700kg. Calculate time for 700kg until its 1100kg and so on.

I managed to get the answer using python pandas and for loop. But I was wondering if there is a simple and better way to do this like in an Excel, Power Query or Power BI.