pythonScope errorMedium

Adding to a global total raises UnboundLocalError

Time: 0:00

What it should do

add_all(nums) should return the sum of the numbers, so add_all([1, 2, 3]) returns 6.

What goes wrong

add_all([1, 2, 3]) raises UnboundLocalError: cannot access local variable 'total' — even though total is defined at the top of the file.

Hints

This is a scope and closure bugs bug

Every callback reports the last value, a counter never increments, UnboundLocalError on a variable you can see.