Add ability to get view when selecting subset of fields.

Add ability to get view when selecting subset of fields in a struct array,
for numpy 1.8.0. Currently a copy is still returned - set WARN_ON_WRITE flag
which will be removed in a future version of numpy.

2 files changed, 8 insertions, 0 deletions

diff --git a/numpy/core/_internal.py b/numpy/core/_internal.py
index 309b53c44..29d21a9bc 100644
--- a/numpy/core/_internal.py
+++ b/numpy/core/_internal.py
@@ -298,6 +298,13 @@ def _index_fields(ary, fields):
     for name in fields:
         newarray[name] = ary[name]
 
+    names = [name for name in fields if name in dt.names]
+    formats = dt.fields[name][0] for name in fields if name in dt.names]
+    offsets = [dt.fields[name][1] for name in fields if name in dt.names]
+
+    view_dtype = {'names':names, 'formats':formats, 'offsets':offsets}
+    view = ary.view(dtype=view_dtype)
+
     return newarray
 
 # Given a string containing a PEP 3118 format specifier,
diff --git a/numpy/core/src/multiarray/mapping.c b/numpy/core/src/multiarray/mapping.c
index cdefb9982..b2643f89f 100644
--- a/numpy/core/src/multiarray/mapping.c
+++ b/numpy/core/src/multiarray/mapping.c
@@ -975,6 +975,7 @@ array_subscript(PyArrayObject *self, PyObject *op)
             }
             obj = PyObject_CallMethod(_numpy_internal,
                     "_index_fields", "OO", self, op);
+            PyArray_ENABLEFLAGS((PyArrayObject*)obj, NPY_ARRAY_WARN_ON_WRITE);
             Py_DECREF(_numpy_internal);
             return obj;
         }