BUG: fix inconsistency with np.array(['']) being truthy

2 files changed, 17 insertions, 0 deletions

diff --git a/numpy/core/src/multiarray/arraytypes.c.src b/numpy/core/src/multiarray/arraytypes.c.src
index c19d31a0d..a7d36ab42 100644
--- a/numpy/core/src/multiarray/arraytypes.c.src
+++ b/numpy/core/src/multiarray/arraytypes.c.src
@@ -2298,6 +2298,10 @@ STRING_nonzero (char *ip, PyArrayObject *ap)
     int i;
     npy_bool nonz = NPY_FALSE;
 
+    if ((len == 1) && (*ip == '\0')) {
+        return NPY_FALSE;
+    }
+
     for (i = 0; i < len; i++) {
         if (!Py_STRING_ISSPACE(*ip)) {
             nonz = NPY_TRUE;
@@ -2334,6 +2338,10 @@ UNICODE_nonzero (npy_ucs4 *ip, PyArrayObject *ap)
         ip = (npy_ucs4 *)buffer;
     }
 
+    if ((len == 1) && (*ip == '\0')) {
+        return NPY_FALSE;
+    }
+
     for (i = 0; i < len; i++) {
         if (!PyArray_UCS4_ISSPACE(*ip)) {
             nonz = NPY_TRUE;
diff --git a/numpy/core/tests/test_multiarray.py b/numpy/core/tests/test_multiarray.py
index e6911d0e3..b0a565b0c 100644
--- a/numpy/core/tests/test_multiarray.py
+++ b/numpy/core/tests/test_multiarray.py
@@ -5731,5 +5731,14 @@ class TestArrayPriority(TestCase):
             assert_(isinstance(f(b, a), self.Other), msg)
 
 
+class TestEmptyStringArray(TestCase):
+
+    def test_empty_bstring_array_is_falsey(self):
+        self.assertFalse(np.array([b'']))
+
+    def test_empty_ustring_array_is_falsey(self):
+        self.assertFalse(np.array([u'']))
+
+
 if __name__ == "__main__":
     run_module_suite()