bpo-32554: Deprecate hashing arbitrary types in random.seed() (GH-15382)

2 files changed, 16 insertions, 0 deletions

diff --git a/Doc/library/random.rst b/Doc/library/random.rst
index 90b8624..1bd1856 100644
--- a/Doc/library/random.rst
+++ b/Doc/library/random.rst
@@ -86,6 +86,11 @@ Bookkeeping functions
    .. versionchanged:: 3.2
       Moved to the version 2 scheme which uses all of the bits in a string seed.
 
+   .. deprecated:: 3.9
+      In the future, the *seed* must be one of the following types:
+      *NoneType*, :class:`int`, :class:`float`, :class:`str`,
+      :class:`bytes`, or :class:`bytearray`.
+
 .. function:: getstate()
 
    Return an object capturing the current internal state of the generator.  This
@@ -316,6 +321,11 @@ Alternative Generator
    Class that implements the default pseudo-random number generator used by the
    :mod:`random` module.
 
+   .. deprecated:: 3.9
+      In the future, the *seed* must be one of the following types:
+      :class:`NoneType`, :class:`int`, :class:`float`, :class:`str`,
+      :class:`bytes`, or :class:`bytearray`.
+
 .. class:: SystemRandom([seed])
 
    Class that uses the :func:`os.urandom` function for generating random numbers
diff --git a/Doc/whatsnew/3.9.rst b/Doc/whatsnew/3.9.rst
index 6615a2e..05a17a5 100644
--- a/Doc/whatsnew/3.9.rst
+++ b/Doc/whatsnew/3.9.rst
@@ -169,6 +169,12 @@ Deprecated
   of Python. For the majority of use cases users can leverage the Abstract Syntax
   Tree (AST) generation and compilation stage, using the :mod:`ast` module.
 
+* The :mod:`random` module currently accepts any hashable type as a
+  possible seed value.  Unfortunately, some of those types are not
+  guaranteed to have a deterministic hash value.  After Python 3.9,
+  the module will restrict its seeds to *None*, :class:`int`,
+  :class:`float`, :class:`str`, :class:`bytes`, and :class:`bytearray`.
+
 
 Removed
 =======