diff options
| -rw-r--r-- | numpy/core/src/multiarray/compiled_base.c | 14 | ||||
| -rw-r--r-- | numpy/lib/tests/test_index_tricks.py | 18 |
2 files changed, 32 insertions, 0 deletions
diff --git a/numpy/core/src/multiarray/compiled_base.c b/numpy/core/src/multiarray/compiled_base.c index c38067681..7ba212464 100644 --- a/numpy/core/src/multiarray/compiled_base.c +++ b/numpy/core/src/multiarray/compiled_base.c @@ -942,6 +942,20 @@ ravel_multi_index_loop(int ravel_ndim, npy_intp *ravel_dims, char invalid; npy_intp j, m; + /* + * Check for 0-dimensional axes unless there is nothing to do. + * An empty array/shape cannot be indexed at all. + */ + if (count != 0) { + for (i = 0; i < ravel_ndim; ++i) { + if (ravel_dims[i] == 0) { + PyErr_SetString(PyExc_ValueError, + "cannot unravel if shape has zero entry (is empty)."); + return NPY_FAIL; + } + } + } + NPY_BEGIN_ALLOW_THREADS; invalid = 0; while (count--) { diff --git a/numpy/lib/tests/test_index_tricks.py b/numpy/lib/tests/test_index_tricks.py index a5cdda074..dbe445c2c 100644 --- a/numpy/lib/tests/test_index_tricks.py +++ b/numpy/lib/tests/test_index_tricks.py @@ -175,6 +175,24 @@ class TestRavelUnravelIndex(object): assert_raises_regex( ValueError, "out of bounds", np.unravel_index, [1], ()) + @pytest.mark.parametrize("mode", ["clip", "wrap", "raise"]) + def test_empty_array_ravel(self, mode): + res = np.ravel_multi_index( + np.zeros((3, 0), dtype=np.intp), (2, 1, 0), mode=mode) + assert(res.shape == (0,)) + + with assert_raises(ValueError): + np.ravel_multi_index( + np.zeros((3, 1), dtype=np.intp), (2, 1, 0), mode=mode) + + def test_empty_array_unravel(self): + res = np.unravel_index(np.zeros(0, dtype=np.intp), (2, 1, 0)) + # res is a tuple of three empty arrays + assert(len(res) == 3) + assert(all(a.shape == (0,) for a in res)) + + with assert_raises(ValueError): + np.unravel_index([1], (2, 1, 0)) class TestGrid(object): def test_basic(self): |