Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/lib/python2.7/py_compile.py", line 117, in compile
    raise py_exc
py_compile.PyCompileError:   File "/in/foo.py", line 13
    print(b,a,sep='')
                 ^
SyntaxError: invalid syntax