diff options
| -rw-r--r-- | Doc/whatsnew/3.1.rst | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/Doc/whatsnew/3.1.rst b/Doc/whatsnew/3.1.rst index 1891038f58..e560bcd80f 100644 --- a/Doc/whatsnew/3.1.rst +++ b/Doc/whatsnew/3.1.rst @@ -384,6 +384,24 @@ New, Improved, and Deprecated Modules (Contributed by Brett Cannon.) +* :mod:`pickle` is now more compatible with Python 2.x when using a + 2.x-compatible protocol (that is, protocol 2 or lower), through translation + of some standard library module names to or from their Python 2.x + equivalents. + + This means that more (protocol 2 or lower) pickles produced by Python 3.1 + will be reusable by Python 2.x, and vice-versa. Standard set objects are + an example of this improvement. + + This has the (unfortunate but unavoidable) side effect that some + protocol 2 pickles produced by Python 3.1 won't be readable with + Python 3.0. The latest pickle protocol, protocol 3, should be used when + migrating data between Python 3.x implementations, as it doesn't attempt + to remain compatible with Python 2.x. + + (Contributed by Alexandre Vassalotti and Antoine Pitrou, :issue:`6137`.) + + Optimizations ============= |