change to version < 3

Author: jreback

pandas/_libs/src/compat_helper.h

@@ -22,10 +22,10 @@ but 3.6.1 in particular changes the behavior of this function slightly
 PANDAS_INLINE int slice_get_indices(PyObject *s, Py_ssize_t length,
                                     Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t *step,
                                     Py_ssize_t *slicelength) {
-#if PY_VERSION_HEX >= 0x03060000
+#if PY_VERSION_HEX >= 0x03000000
   return PySlice_GetIndicesEx(s, length, start, stop, step, slicelength);
 #else
-  return PySlice_GetIndicesEx(<PySliceObject *>s, length, start, stop, step, slicelength);
+  return PySlice_GetIndicesEx((PySliceObject *)s, length, start, stop, step, slicelength);
 #endif
 }