Issue #10601: sys.displayhook uses 'backslashreplace' error handler on
UnicodeEncodeError.
diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst
index c7aa214..95d1cf9 100644
--- a/Doc/library/sys.rst
+++ b/Doc/library/sys.rst
@@ -99,13 +99,39 @@
.. function:: displayhook(value)
- If *value* is not ``None``, this function prints it to ``sys.stdout``, and saves
- it in ``builtins._``.
+ If *value* is not ``None``, this function prints ``repr(value)`` to
+ ``sys.stdout``, and saves *value* in ``builtins._``. If ``repr(value)`` is
+ not encodable to ``sys.stdout.encoding`` with ``sys.stdout.errors`` error
+ handler (which is probably ``'strict'``), encode it to
+ ``sys.stdout.encoding`` with ``'backslashreplace'`` error handler.
``sys.displayhook`` is called on the result of evaluating an :term:`expression`
entered in an interactive Python session. The display of these values can be
customized by assigning another one-argument function to ``sys.displayhook``.
+ Pseudo-code::
+
+ def displayhook(value):
+ if value is None:
+ return
+ # Set '_' to None to avoid recursion
+ builtins._ = None
+ text = repr(value)
+ try:
+ sys.stdout.write(text)
+ except UnicodeEncodeError:
+ bytes = text.encode(sys.stdout.encoding, 'backslashreplace')
+ if hasattr(sys.stdout, 'buffer'):
+ sys.stdout.buffer.write(bytes)
+ else:
+ text = bytes.decode(sys.stdout.encoding, 'strict')
+ sys.stdout.write(text)
+ sys.stdout.write("\n")
+ builtins._ = value
+
+ .. versionchanged:: 3.2
+ Use ``'backslashreplace'`` error handler on :exc:`UnicodeEncodeError`.
+
.. function:: excepthook(type, value, traceback)