MAINT: np.delete keep old out of bound/negative index behavior

2 files changed, 36 insertions, 19 deletions

diff --git a/numpy/lib/function_base.py b/numpy/lib/function_base.py
index 81cfecb9d..d67b97b1d 100644
--- a/numpy/lib/function_base.py
+++ b/numpy/lib/function_base.py
@@ -3386,7 +3386,7 @@ def meshgrid(*xi, **kwargs):
 def delete(arr, obj, axis=None):
     """
     Return a new array with sub-arrays along an axis deleted. For a one
-    dimensional array, this returns those entries not returned by `arr[obj,]`.
+    dimensional array, this returns those entries not returned by `arr[obj]`.
 
     Parameters
     ----------
@@ -3453,9 +3453,9 @@ def delete(arr, obj, axis=None):
         ndim = arr.ndim;
         axis = ndim-1;
     if ndim == 0:
-        warnings.warn("in the future the special handleing of scalars "
+        warnings.warn("in the future the special handling of scalars "
                       "will be removed from delete and raise an error",
-                      FutureWarning)
+                      DeprecationWarning)
         if wrap:
             return wrap(arr)
         else:
@@ -3517,15 +3517,15 @@ def delete(arr, obj, axis=None):
 
     _obj = obj
     obj = np.asarray(obj)
-    # After removing the special handling of booleans, the size == 1 check
-    # can be just replaced with something else (like integer check)
-    # and there need not be any conversion to an array at all.
+    # After removing the special handling of booleans and out of
+    # bounds values, the conversion to the array can be removed.
     if obj.dtype == bool:
         warnings.warn("in the future insert will treat boolean arrays "
                       "and array-likes as boolean index instead "
                       "of casting it to integer", FutureWarning)
         obj = obj.astype(intp)
-    if obj.size == 1:
+    if isinstance(_obj, (int, long, integer)):
+        # optimization for a single value
         obj = obj.item()
         if (obj < -N or obj >=N):
             raise IndexError("index %i is out of bounds for axis "
@@ -3549,6 +3549,20 @@ def delete(arr, obj, axis=None):
                 "will result in an error in the future", DeprecationWarning)
             obj = obj.astype(intp)
         keep = ones(N, dtype=bool)
+
+        # Test if there are out of bound indices, this is deprecated
+        inside_bounds = (obj < N) & (obj >= -N)
+        if not inside_bounds.all():
+            warnings.warn("in the future out of bounds indices will raise an "
+                          "error instead of being ignored by `numpy.delete`.",
+                          DeprecationWarning)
+            obj = obj[inside_bounds]
+        positive_indices = obj >= 0
+        if not positive_indices.all():
+            warnings.warn("in the future negative indices will not be ignored "
+                          "by `numpy.delete`.", FutureWarning)
+            obj = obj[positive_indices]
+
         keep[obj,] = False
         slobj[axis] = keep
         new = arr[slobj]
@@ -3660,9 +3674,9 @@ def insert(arr, obj, values, axis=None):
         ndim = arr.ndim
         axis = ndim-1
     if (ndim == 0):
-        warnings.warn("in the future the special handleing of scalars "
+        warnings.warn("in the future the special handling of scalars "
                       "will be removed from insert and raise an error",
-                      FutureWarning)
+                      DeprecationWarning)
         arr = arr.copy()
         arr[...] = values
         if wrap:
diff --git a/numpy/lib/tests/test_function_base.py b/numpy/lib/tests/test_function_base.py
index 06d202bbb..ae68be41f 100644
--- a/numpy/lib/tests/test_function_base.py
+++ b/numpy/lib/tests/test_function_base.py
@@ -214,9 +214,9 @@ class TestInsert(TestCase):
         # This is an error in the future
         a = np.array(1)
         with warnings.catch_warnings(record=True) as w:
-            warnings.filterwarnings('always', '', FutureWarning)
+            warnings.filterwarnings('always', '', DeprecationWarning)
             assert_equal(insert(a, [], 2, axis=0), np.array(2))
-            assert_(w[0].category is FutureWarning)
+            assert_(w[0].category is DeprecationWarning)
 
     def test_subclass(self):
         class SubClass(np.ndarray):
@@ -357,14 +357,15 @@ class TestDelete(TestCase):
     def _check_inverse_of_slicing(self, indices):
         a_del = delete(self.a, indices)
         nd_a_del = delete(self.nd_a, indices, axis=1)
+        msg = 'Delete failed for obj: %r' % indices
         # NOTE: The cast should be removed after warning phase for bools
-        if not isinstance(indices, slice):
+        if not isinstance(indices, (slice, int, long, np.integer)):
             indices = np.asarray(indices, dtype=np.intp)
+            indices = indices[(indices >= 0) & (indices < 5)]
         assert_array_equal(setxor1d(a_del, self.a[indices,]), self.a,
-                           err_msg='Delete failed for obj: %r' % indices)
+                           err_msg=msg)
         xor = setxor1d(nd_a_del[0,:,0], self.nd_a[0,indices,0])
-        assert_array_equal(xor, self.nd_a[0,:,0],
-                           err_msg='Delete failed for obj: %r' % indices)
+        assert_array_equal(xor, self.nd_a[0,:,0], err_msg=msg)
 
     def test_slices(self):
         lims = [-6, -2, 0, 1, 2, 4, 5]
@@ -376,11 +377,13 @@ class TestDelete(TestCase):
                     self._check_inverse_of_slicing(s)
 
     def test_fancy(self):
-        self._check_inverse_of_slicing([0, -1, 2, 2])
+        # Deprecation/FutureWarning tests should be kept after change.
         self._check_inverse_of_slicing(np.array([[0,1],[2,1]]))
-        assert_raises(IndexError, delete, self.a, [100])
+        assert_raises(DeprecationWarning, delete, self.a, [100])
+        assert_raises(DeprecationWarning, delete, self.a, [-100])
         with warnings.catch_warnings(record=True) as w:
             warnings.filterwarnings('always', '', FutureWarning)
+            self._check_inverse_of_slicing([0, -1, 2, 2])
             obj = np.array([True, False, False], dtype=bool)
             self._check_inverse_of_slicing(obj)
             assert_(w[0].category is FutureWarning)
@@ -393,9 +396,9 @@ class TestDelete(TestCase):
     def test_0d(self):
         a = np.array(1)
         with warnings.catch_warnings(record=True) as w:
-            warnings.filterwarnings('always', '', FutureWarning)
+            warnings.filterwarnings('always', '', DeprecationWarning)
             assert_equal(delete(a, [], axis=0), a)
-            assert_(w[0].category is FutureWarning)
+            assert_(w[0].category is DeprecationWarning)
 
     def test_subclass(self):
         class SubClass(np.ndarray):