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bpo-42179: Doc/tutorial: Remove mention of __cause__ (GH-23162)

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Inada Naoki 2020-11-06 11:45:01 +09:00 committed by GitHub
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1 changed files with 10 additions and 9 deletions
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Doc/tutorial/errors.rst
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@ -273,15 +273,15 @@ Exception Chaining
==================
The :keyword:`raise` statement allows an optional :keyword:`from` which enables
chaining exceptions by setting the ``__cause__`` attribute of the raised
exception. For example::
chaining exceptions. For example::
raise RuntimeError from OSError
# exc must be exception instance or None.
raise RuntimeError from exc
This can be useful when you are transforming exceptions. For example::
>>> def func():
... raise IOError
... raise IOError
...
>>> try:
... func()
@ -297,12 +297,11 @@ This can be useful when you are transforming exceptions. For example::
<BLANKLINE>
Traceback (most recent call last):
File "<stdin>", line 4, in <module>
RuntimeError
RuntimeError: Failed to open database
The expression following the :keyword:`from` must be either an exception or
``None``. Exception chaining happens automatically when an exception is raised
inside an exception handler or :keyword:`finally` section. Exception chaining
can be disabled by using ``from None`` idiom:
Exception chaining happens automatically when an exception is raised inside an
:keyword:`except` or :keyword:`finally` section. Exception chaining can be
disabled by using ``from None`` idiom:
>>> try:
... open('database.sqlite')
@ -313,6 +312,8 @@ can be disabled by using ``from None`` idiom:
File "<stdin>", line 4, in <module>
RuntimeError
For more information about chaining mechanics, see :ref:`bltin-exceptions`.
.. _tut-userexceptions: