$($a$)$ Write a function partial$\_$sums that takes a list of lists called data as its argument.

The function should return a list containing the sum of each inner list appearing in

data. Note that the inner lists that are the elements of data can have different lengths;

if one such list contains any values that cannot be summed $($for instance strings$),$ the

corresponding sum should be computed as None. Empty inner lists should sum to $0.$

So for instance the call partial$\_$sums $(,[\text{'}$James$\text{'},1],[2,$ 'Bond'$],$

$[]$