This is called tuple unpacking.
a, b = 1, 2
print a # 1
print b # 2
line.split(...) returns two elements which get unpacked to role, line_spoken.
So, for example if line.split(...) returns ['Monty', 'Python'], role would get 'Monty' and line_spoken would get 'Python'.
solved What does the role and line_spoken do in code?