Merge pull request #10151 from eric-wieser/integer-type-__name__

BUG: Numpy scalar types sometimes have the same name

2 files changed, 29 insertions, 7 deletions

diff --git a/numpy/core/tests/test_dtype.py b/numpy/core/tests/test_dtype.py
index f5ca775ef..d2fbbae5b 100644
--- a/numpy/core/tests/test_dtype.py
+++ b/numpy/core/tests/test_dtype.py
@@ -963,13 +963,6 @@ class TestDtypeAttributes(object):
         new_dtype = np.dtype(dtype.descr)
         assert_equal(new_dtype.itemsize, 16)
 
-    @pytest.mark.parametrize('t', np.typeDict.values())
-    def test_name_builtin(self, t):
-        name = t.__name__
-        if name.endswith('_'):
-            name = name[:-1]
-        assert_equal(np.dtype(t).name, name)
-
     def test_name_dtype_subclass(self):
         # Ticket #4357
         class user_def_subcls(np.void):
diff --git a/numpy/core/tests/test_numerictypes.py b/numpy/core/tests/test_numerictypes.py
index d0ff5578a..387740e35 100644
--- a/numpy/core/tests/test_numerictypes.py
+++ b/numpy/core/tests/test_numerictypes.py
@@ -498,3 +498,32 @@ class TestDocStrings(object):
             assert_('int64' in np.int_.__doc__)
         elif np.int64 is np.longlong:
             assert_('int64' in np.longlong.__doc__)
+
+
+class TestScalarTypeNames:
+    # gh-9799
+
+    numeric_types = [
+        np.byte, np.short, np.intc, np.int_, np.longlong,
+        np.ubyte, np.ushort, np.uintc, np.uint, np.ulonglong,
+        np.half, np.single, np.double, np.longdouble,
+        np.csingle, np.cdouble, np.clongdouble,
+    ]
+
+    def test_names_are_unique(self):
+        # none of the above may be aliases for each other
+        assert len(set(self.numeric_types)) == len(self.numeric_types)
+
+        # names must be unique
+        names = [t.__name__ for t in self.numeric_types]
+        assert len(set(names)) == len(names)
+
+    @pytest.mark.parametrize('t', numeric_types)
+    def test_names_reflect_attributes(self, t):
+        """ Test that names correspond to where the type is under ``np.`` """
+        assert getattr(np, t.__name__) is t
+
+    @pytest.mark.parametrize('t', numeric_types)
+    def test_names_are_undersood_by_dtype(self, t):
+        """ Test the dtype constructor maps names back to the type """
+        assert np.dtype(t.__name__).type is t