DOC: Clarify the effect of None parameters passed to ndarray.view

Make it clear that explicitly passing None for dtype or type will
behave differently than omitting these parameters.
See also #14875

1 files changed, 9 insertions, 4 deletions

diff --git a/numpy/core/_add_newdocs.py b/numpy/core/_add_newdocs.py
index 36fc9d7d6..5ff12a2c7 100644
--- a/numpy/core/_add_newdocs.py
+++ b/numpy/core/_add_newdocs.py
@@ -4129,14 +4129,14 @@ add_newdoc('numpy.core.multiarray', 'ndarray', ('view',
     Parameters
     ----------
     dtype : data-type or ndarray sub-class, optional
-        Data-type descriptor of the returned view, e.g., float32 or int16. The
-        default, None, results in the view having the same data-type as `a`.
+        Data-type descriptor of the returned view, e.g., float32 or int16.
+        Omitting it results in the view having the same data-type as `a`.
         This argument can also be specified as an ndarray sub-class, which
         then specifies the type of the returned object (this is equivalent to
         setting the ``type`` parameter).
     type : Python type, optional
-        Type of the returned view, e.g., ndarray or matrix.  Again, the
-        default None results in type preservation.
+        Type of the returned view, e.g., ndarray or matrix.  Again, omission
+        of the parameter results in type preservation.
 
     Notes
     -----
@@ -4160,6 +4160,11 @@ add_newdoc('numpy.core.multiarray', 'ndarray', ('view',
     defined as a slice or transpose, etc., the view may give different
     results.
 
+    Passing None explicitly for ``dtype`` is different from omitting the
+    parameter, since the former invokes ``dtype(None)`` which is an alias for
+    ``dtype('float_')``. Similarly, explicitly passing None for ``type``
+    is an error.
+
 
     Examples
     --------