I have a list of tuples where each tuple within the list contains 3 elements.

- Is the year in 4 digits i.e 2014
- Month in integer i.e from 1-12
- And another integer value which is the number of months needed to be subtracted.

So if the date is May 2020 and I want to subtract 3 months then the tuple would look like (2020,5,3) . And I need to loop over such tuples to calculate the month after subtracting the integer. So in the above case it would be 5-3 = 2 i.e February 2020. Any idea how to create a function to do this?