pythonNull / UndefinedMedium

Accumulator throwing TypeError

Time: 0:00

What it should do

total_score(scores, names) should add up the scores for the named players, treating anyone without a score as 0.

What goes wrong

total_score({'a': 5}, ['a', 'b']) raises TypeError: unsupported operand type(s) for +: 'int' and 'NoneType'.

Hints

This is a null and undefined errors bug

Cannot read properties of undefined, NoneType has no attribute, NaN appearing from nowhere.