bpo-38870: Extend subject of ast.unparse warnings (GH-21053)
- Mention that some compiler optimizations might not roundtrip
exactly (such as constant tuples and frozensets).
- Add a warning about it might raise RecursionError on very
complex expressions due to recursive unparsing aspect of ast.unparse
diff --git a/Doc/library/ast.rst b/Doc/library/ast.rst
index 6c6ad01..25cb178 100644
--- a/Doc/library/ast.rst
+++ b/Doc/library/ast.rst
@@ -1553,7 +1553,12 @@
.. warning::
The produced code string will not necessarily be equal to the original
- code that generated the :class:`ast.AST` object.
+ code that generated the :class:`ast.AST` object (without any compiler
+ optimizations, such as constant tuples/frozensets).
+
+ .. warning::
+ Trying to unparse a highly complex expression would result with
+ :exc:`RecursionError`.
.. versionadded:: 3.9