My method returns
Invalid base type for memoryview slice: string
The easiest way is probably just to copy to a Python list.
For the sake of this answer I'm assuming you've wrapped your array similar to this answer and called it
arrstr4. The code then looks something like:
def f(): cdef arrstr4 res = your_cplus_plus_function() py_res =  for i in range(4): py_res.append(res[i]) # take advantage of autoconversion to python string return py_res