Answer:
'!'
Step-by-step explanation:
In python, a string can be traversed from end very easily by using negative indexes, so, if index 0 points to the first element of the string, then, index -1 will point to the last element of the string, that is why, when data[-1] is printed last element of data, which is '!' is printed. Also, it can take more parameters separated by a colon, which are end index and step.