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PEP 830: Formatting + typo + update name #4900

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a02a8d4
Formatting
hugovk Apr 13, 2026
c2720fe
Typo
hugovk Apr 13, 2026
86102f9
dcolascione -> +Daniel Colascione
hugovk Apr 13, 2026
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24 changes: 12 additions & 12 deletions peps/pep-0830.rst
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Original file line number Diff line number Diff line change
Expand Up @@ -144,7 +144,7 @@ Display Format
Timestamps are appended to the exception message line in tracebacks using
the format ``<@timestamp>``. Example with ``iso``:

.. code-block:: text
.. code-block:: pytb

Traceback (most recent call last):
File "<stdin>", line 3, in california_raisin
Expand Down Expand Up @@ -208,7 +208,7 @@ occasional varying 1-2% measurement noise that could not be reliably
reproduced. Below the benchmarking setup noise threshold as far as the author
is concerned.

What about the special case performance optimiaztion? If I omit the two line
What about the special case performance optimization? If I omit the two-line
special case to avoid collecting timestamps on ``StopIteration`` and
``StopAsyncIteration`` in ``Objects/exception.c``, only a single benchmark
showed a regression: ``async_generators``. That one would reliably run on the
Expand All @@ -219,7 +219,7 @@ demonstrates the importance of that optimization.
I used ``configure --enable-optimizations`` builds for my benchmarks and ran
them using commands such as:

.. code-block:: text
.. code-block:: shell

pyperformance run -p baseline-3a7df632c96/build/python -o baseline-eopt.json
pyperformance run -p traceback-timestamps/build/python -o traceback-timestamps-default-eopt.json
Expand Down Expand Up @@ -250,30 +250,30 @@ Pickled Exception Examples

With traceback timestamp collection enabled:

.. code-block:: text
.. code-block:: console

❯ build/python -X traceback_timestamps=iso -c 'import pickle; print(pickle.dumps(RuntimeError("pep-830"), protocol=pickle.HIGHEST_PROTOCOL))'
$ build/python -X traceback_timestamps=iso -c 'import pickle; print(pickle.dumps(RuntimeError("pep-830"), protocol=pickle.HIGHEST_PROTOCOL))'
b'\x80\x05\x95L\x00\x00\x00\x00\x00\x00\x00\x8c\x08builtins\x94\x8c\x0cRuntimeError\x94\x93\x94\x8c\x07pep-830\x94\x85\x94R\x94}\x94\x8c\x10__timestamp_ns__\x94\x8a\x08\xf4\xd8\x94`\x15\xaf\xa5\x18sb.'

The special case for ``StopIteration`` means it does not carry the dict with timestamp data:

.. code-block:: text
.. code-block:: console

❯ build/python -X traceback_timestamps=iso -c 'import pickle; print(pickle.dumps(StopIteration("pep-830"), protocol=pickle.HIGHEST_PROTOCOL))'
$ build/python -X traceback_timestamps=iso -c 'import pickle; print(pickle.dumps(StopIteration("pep-830"), protocol=pickle.HIGHEST_PROTOCOL))'
b'\x80\x05\x95,\x00\x00\x00\x00\x00\x00\x00\x8c\x08builtins\x94\x8c\rStopIteration\x94\x93\x94\x8c\x07pep-830\x94\x85\x94R\x94.'

Nor do exceptions carry the timestamp when the feature is disabled (the default):

.. code-block:: text
.. code-block:: console

❯ build/python -X traceback_timestamps=0 -c 'import pickle; print(pickle.dumps(RuntimeError("pep-830"), protocol=pickle.HIGHEST_PROTOCOL))'
$ build/python -X traceback_timestamps=0 -c 'import pickle; print(pickle.dumps(RuntimeError("pep-830"), protocol=pickle.HIGHEST_PROTOCOL))'
b'\x80\x05\x95+\x00\x00\x00\x00\x00\x00\x00\x8c\x08builtins\x94\x8c\x0cRuntimeError\x94\x93\x94\x8c\x07pep-830\x94\x85\x94R\x94.'

Which matches what Python 3.13 produces:

.. code-block:: text
.. code-block:: console

❯ python3.13 -c 'import pickle; print(pickle.dumps(RuntimeError("pep-830"), protocol=pickle.HIGHEST_PROTOCOL))'
$ python3.13 -c 'import pickle; print(pickle.dumps(RuntimeError("pep-830"), protocol=pickle.HIGHEST_PROTOCOL))'
b'\x80\x05\x95+\x00\x00\x00\x00\x00\x00\x00\x8c\x08builtins\x94\x8c\x0cRuntimeError\x94\x93\x94\x8c\x07pep-830\x94\x85\x94R\x94.'

Maintenance Burden
Expand Down Expand Up @@ -397,7 +397,7 @@ Acknowledgements
================

Thanks to Nathaniel J. Smith for the original idea suggestion, and to
``@dcolascione`` for initial 2025 review feedback on the implementation.
Daniel Colascione for initial 2025 review feedback on the implementation.


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