1 | initial version |
The second is a syntax error in Python 2. In Python 3, the second one is valid. To see the difference, print b after both cases and compare. Hint: (a, *b, c) = (1,2,3,4) does not give an error.
This is really a python question. It has very little to do with sage specifically (especially because it doesn't quite run flawlessly on python 3 yet).