BUG: loadtxt: There was some extra nesting for subarray dtypes (Ticket #1936)

2 files changed, 30 insertions, 5 deletions

diff --git a/numpy/lib/npyio.py b/numpy/lib/npyio.py
index 30c8cc5be..cb71ffad5 100644
--- a/numpy/lib/npyio.py
+++ b/numpy/lib/npyio.py
@@ -705,11 +705,10 @@ def loadtxt(fname, dtype=float, comments='#', delimiter=None,
             if len(shape) == 0:
                 return ([dt.base], None)
             else:
-                packing = [(shape[-1], tuple)]
+                packing = [(shape[-1], list)]
                 if len(shape) > 1:
-                    for dim in dt.shape[-2:0:-1]:
-                        packing = [(dim*packing[0][0],packing*dim)]
-                    packing = packing*shape[0]
+                    for dim in dt.shape[-2::-1]:
+                        packing = [(dim*packing[0][0], packing*dim)]
                 return ([dt.base] * int(np.prod(dt.shape)), packing)
         else:
             types = []
@@ -718,7 +717,11 @@ def loadtxt(fname, dtype=float, comments='#', delimiter=None,
                 tp, bytes = dt.fields[field]
                 flat_dt, flat_packing = flatten_dtype(tp)
                 types.extend(flat_dt)
-                packing.append((len(flat_dt),flat_packing))
+                # Avoid extra nesting for subarrays
+                if len(tp.shape) > 0:
+                    packing.extend(flat_packing)
+                else:
+                    packing.append((len(flat_dt), flat_packing))
             return (types, packing)
 
     def pack_items(items, packing):
@@ -727,6 +730,8 @@ def loadtxt(fname, dtype=float, comments='#', delimiter=None,
             return items[0]
         elif packing is tuple:
             return tuple(items)
+        elif packing is list:
+            return list(items)
         else:
             start = 0
             ret = []
diff --git a/numpy/lib/tests/test_regression.py b/numpy/lib/tests/test_regression.py
index c0cfff9a5..c244aea87 100644
--- a/numpy/lib/tests/test_regression.py
+++ b/numpy/lib/tests/test_regression.py
@@ -202,5 +202,25 @@ class TestRegression(TestCase):
         except:
             raise AssertionError()
 
+    def test_loadtxt_fields_subarrays(self):
+        # For ticket #1936
+        from StringIO import StringIO
+        dt = [("a", 'u1', 2), ("b", 'u1', 2)]
+        x = np.loadtxt(StringIO("0 1 2 3"), dtype=dt)
+        assert_equal(x, np.array([((0, 1), (2, 3))], dtype=dt))
+
+        dt = [("a", [("a", 'u1', (1,3)), ("b", 'u1')])]
+        x = np.loadtxt(StringIO("0 1 2 3"), dtype=dt)
+        assert_equal(x, np.array([(((0,1,2), 3),)], dtype=dt))
+
+        dt = [("a", 'u1', (2,2))]
+        x = np.loadtxt(StringIO("0 1 2 3"), dtype=dt)
+        assert_equal(x, np.array([(((0, 1), (2, 3)),)], dtype=dt))
+
+        dt = [("a", 'u1', (2,3,2))]
+        x = np.loadtxt(StringIO("0 1 2 3 4 5 6 7 8 9 10 11"), dtype=dt)
+        data = [((((0,1), (2,3), (4,5)), ((6,7), (8,9), (10,11))),)]
+        assert_equal(x, np.array(data, dtype=dt))
+
 if __name__ == "__main__":
     run_module_suite()