Item 6: Functions need return statement

[EricRa]

I'm not sure if this was intentionally omitted for brevity or not, but the bubble sort functions in Item 6 do not include a return statement needed for the code to function as written.

For example, the bubble_sort function demonstrating swapping of variable values should include a "return a" at the bottom of the function.

[KirkSuD]

The functions sort the list in place, no copy is made, so there's no need to return it. Just like a.sort() & random.shuffle(a). And the example code never uses return value of bubble_sort(), so it's fine.

[bslatkin]

Thank you for the report! I agree with @KirkSuD about why this is fine.