In general, it's preferable not to use parentheses in 2.7. While it's not a syntax error, the semantics are different from 3.x, specifically when you print multiple, comma-separated values (for single values, the result is the same).
For example, using print('foo', 'bar') will print ('foo', 'bar') in 2.7, but foo bar in 3.x (what you'd get without the parentheses in 2.7). So 2.7 doesn't actually treat the parentheses as part of a function call, but rather creates a tuple with both values and prints that. It would be equivalent to:
t = ('foo', 'bar') # create a tuple
print t
So it'll still work, but the result might not be what you want in most cases.