FIX: align draw's Python size dispatch with the jitted path (#918)

quantecon/random/tests/test_utilities.py

@@ -125,6 +125,17 @@ def test_return_types(self):
             out = func(self.cdf, size)
             assert_(out.shape == (size,))
 
+    def test_numpy_integer_size(self):
+        """
+        A numpy integer `size` must request an array, as a Python `int`
+        does and as the jitted path already did. See #918.
+
+        """
+        size = np.int64(10)
+        for func in self.draw_funcs:
+            out = func(self.cdf, size)
+            assert_(out.shape == (size,))
+
     def test_return_values(self):
         for func in self.draw_funcs:
             out = func(self.cdf)

quantecon/random/utilities.py

@@ -246,7 +246,10 @@ def draw(cdf, size=None, rng=None):
     """
     if rng is None:
         rng = np.random
-    if isinstance(size, int):
+    # `bool` subclasses `int` in Python but Numba types it as `Boolean`,
+    # not `Integer`, so the exclusion keeps this branch in step with the
+    # `@overload` implementation below. See #918.
+    if isinstance(size, (int, np.integer)) and not isinstance(size, bool):
         rs = rng.random(size)
         out = np.searchsorted(cdf, rs, side='right')
         return out