In this case, out of habit of being a python programmer, I had used -1 to get to the last index, which is supposed to be incorrect, swirl did acknowledge that it is incorrect, however moved on to the next part.
The 2nd instance I found was in the mad_libs function where I did not pass in named arguments and the output string just returned blanks in place of the args variables , however SWIRL accepted it as a correct submission.
The 2nd instance I found was in the mad_libs function where I did not pass in named arguments and the output string just returned blanks in place of the args variables , however SWIRL accepted it as a correct submission.
Hope it helps. Cheers!