Create new list based on old list of Lot-id and latest date

I have a file that has two columns in it.

The first column is the Lot-id column.
The 2nd column is the Date column.

What i want to do is this:
For a given lot-id i want to find the latest date.

Then i want to create a new list such that i have a single row for each lotid with the latest date for listed in the date col for that lot.

any ideas?