The print function already adds a newline for you, so if you just want to print followed by a newline, do (parens mandatory since this is Python 3):
print(a)
If the goal is to print the elements of a each separated by newlines, you can either loop explicitly:
for x in a:
print(x)
or abuse star unpacking to do it as a single statement, using sep to split outputs to different lines:
print(*a, sep="\n")
If you want a blank line between outputs, not just a line break, add end="\n\n" to the first two, or change sep to sep="\n\n" for the final option.
\nafterawill improve the readability... maybe you want to print a new line after each combination?for combination in a: print(combination)will do what you want.