how would i code this in python

Def sum_evens_2d (xss): Given a "two-dimensional list" of integers - that is, a list where each value in it is a list of integers-find all the even numbers and sum them together. You will need more than a single loop for this! assume that xss is a list where each value is a list of integers. Restriction: you may not call sum (). (It would have included the odds anyways). Examples: sum_evens_2d ([[l, 2, 3], [4, 5, 6]]) rightarrow 2 + 4 + 6 = = 12 sum_evens_2d ([[1, 3, 5], [7, 9, 11]]) rightarrow 0 sum_evens_2d ([[l, 2, 3], [4, 5], [6], [7, 8, 9]]) rightarrow 2 + 4 + 6 + 8 = = 20