Review (jreback)

Author: h-vetinari

pandas/core/reshape/concat.py

@@ -237,7 +237,7 @@ def concat(objs, axis=0, join='outer', join_axes=None, ignore_index=False,
         if ndim == 2:
             other_axis = 1 if axis == 0 else 0  # switches between 0 & 1
             res = res.reindex(join_axes[0], axis=other_axis)
-        else:  # 3 for Panel; Panel4D already deprecated
+        elif ndim == 3:  # Panel
             other_axes = list(range(res.ndim))
             other_axes.pop(axis)
             for i in range(ndim - 1):