bpo-43905: Expand dataclasses.astuple() and asdict() docs

Doc/library/dataclasses.rst

@@ -349,13 +349,18 @@ Module contents
    Converts the dataclass ``instance`` to a tuple (by using the
    factory function ``tuple_factory``).  Each dataclass is converted
    to a tuple of its field values.  dataclasses, dicts, lists, and
-   tuples are recursed into.
+   tuples are recursed into. Other objects are copied with
+   :func:`copy.deepcopy`.
 
    Continuing from the previous example::
 
      assert astuple(p) == (10, 20)
      assert astuple(c) == ([(0, 0), (10, 4)],)
 
+   To create a shallow copy, the following workaround may be used::
+
+     tuple(getattr(instance, field.name) for field in dataclasses.fields(instance))
+
    Raises :exc:`TypeError` if ``instance`` is not a dataclass instance.
 
 .. function:: make_dataclass(cls_name, fields, *, bases=(), namespace=None, init=True, repr=True, eq=True, order=False, unsafe_hash=False, frozen=False, match_args=True, kw_only=False, slots=False)

Misc/NEWS.d/next/Documentation/2021-05-24-05-00-12.bpo-43905.tBIndE.rst

@@ -0,0 +1,2 @@
+Expanded ``dataclasses.astuple()`` docs, warning about deepcopy being applied
+and providing a workaround.