ENH: sparse: enhance dtype checking in constructors (scipy#22113)

* tests of invalid dtype checking

* complete dtype checking in constructor

* fix linting

Author: dschult

scipy/sparse/_bsr.py

@@ -137,7 +137,7 @@ def __init__(self, arg1, shape=None, dtype=None, copy=False,
                 self._shape = check_shape(shape)
 
         if dtype is not None:
-            self.data = self.data.astype(dtype, copy=False)
+            self.data = self.data.astype(getdtype(dtype, self.data), copy=False)
 
         self.check_format(full_check=False)
 

scipy/sparse/_coo.py

@@ -65,13 +65,13 @@ def __init__(self, arg1, shape=None, dtype=None, copy=False, *, maxprint=None):
             if issparse(arg1):
                 if arg1.format == self.format and copy:
                     self.coords = tuple(idx.copy() for idx in arg1.coords)
-                    self.data = arg1.data.copy()
+                    self.data = arg1.data.astype(getdtype(dtype, arg1))  # copy=True
                     self._shape = check_shape(arg1.shape, allow_nd=self._allow_nd)
                     self.has_canonical_format = arg1.has_canonical_format
                 else:
                     coo = arg1.tocoo()
                     self.coords = tuple(coo.coords)
-                    self.data = coo.data
+                    self.data = coo.data.astype(getdtype(dtype, coo), copy=False)
                     self._shape = check_shape(coo.shape, allow_nd=self._allow_nd)
                     self.has_canonical_format = False
             else:
@@ -92,16 +92,12 @@ def __init__(self, arg1, shape=None, dtype=None, copy=False, *, maxprint=None):
                 coords = M.nonzero()
                 self.coords = tuple(idx.astype(index_dtype, copy=False)
                                      for idx in coords)
-                self.data = M[coords]
+                self.data = getdata(M[coords], copy=copy, dtype=dtype)
                 self.has_canonical_format = True
 
         if len(self._shape) > 2:
             self.coords = tuple(idx.astype(np.int64, copy=False) for idx in self.coords)
 
-        if dtype is not None:
-            newdtype = getdtype(dtype)
-            self.data = self.data.astype(newdtype, copy=False)
-
         self._check()
 
     @property

scipy/sparse/tests/test_base.py

@@ -2183,6 +2183,15 @@ def test_size_zero_conversions(self):
             assert_array_equal(spm.todok().toarray(), m)
             assert_array_equal(spm.tobsr().toarray(), m)
 
+    def test_dtype_check(self):
+        a = np.array([[3.5, 0, 1.1], [0, 0, 0]], dtype=np.float16)
+        with assert_raises(ValueError, match="does not support dtype"):
+            self.spcreator(a)
+
+        A32 = self.spcreator(a.astype(np.float32))
+        with assert_raises(ValueError, match="does not support dtype"):
+            self.spcreator(A32, dtype=np.float16)
+
     def test_pickle(self):
         import pickle
         sup = suppress_warnings()