Update documentation to note that in some circumstances,
KeyboardInterrupt may cause code to enter an inconsistent state. Also
document sample workaround to avoid KeyboardInterrupt, if needed.
1. SyntaxError args have a tuple of other attributes.
2. Attributes are adjusted for errors in f-string field expressions.
3. Compile() can raise SyntaxErrors.
Links for 'raise Exception from x' target to 'The raise statement' (7.8) section instead of 'The import statement' (7.11) section.
There are more modified links than in the bug report because I searched some other ones which can get the same improvement.
To improve the user experience understanding what part of the error messages associated with SyntaxErrors is wrong, we can highlight the whole error range and not only place the caret at the first character. In this way:
>>> foo(x, z for z in range(10), t, w)
File "<stdin>", line 1
foo(x, z for z in range(10), t, w)
^
SyntaxError: Generator expression must be parenthesized
becomes
>>> foo(x, z for z in range(10), t, w)
File "<stdin>", line 1
foo(x, z for z in range(10), t, w)
^^^^^^^^^^^^^^^^^^^^
SyntaxError: Generator expression must be parenthesized
When printing NameError raised by the interpreter, PyErr_Display
will offer suggestions of simmilar variable names in the function that the exception
was raised from:
>>> schwarzschild_black_hole = None
>>> schwarschild_black_hole
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
NameError: name 'schwarschild_black_hole' is not defined. Did you mean: schwarzschild_black_hole?
When printing AttributeError, PyErr_Display will offer suggestions of similar
attribute names in the object that the exception was raised from:
>>> collections.namedtoplo
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AttributeError: module 'collections' has no attribute 'namedtoplo'. Did you mean: namedtuple?
See [PEP 597](https://www.python.org/dev/peps/pep-0597/).
* Add `-X warn_default_encoding` and `PYTHONWARNDEFAULTENCODING`.
* Add EncodingWarning
* Add io.text_encoding()
* open(), TextIOWrapper() emits EncodingWarning when encoding is omitted and warn_default_encoding is enabled.
* _pyio.TextIOWrapper() uses UTF-8 as fallback default encoding used when failed to import locale module. (used during building Python)
* bz2, configparser, gzip, lzma, pathlib, tempfile modules use io.text_encoding().
* What's new entry
Enhance the documentation of the Python startup, filesystem encoding
and error handling, locale encoding. Add a new "Python UTF-8 Mode"
section.
* Add "locale encoding" and "filesystem encoding and error handler"
to the glossary
* Remove documentation from Include/cpython/initconfig.h: move it to
Doc/c-api/init_config.rst.
* Doc/c-api/init_config.rst:
* Document command line options and environment variables
* Document default values.
* Add a new "Python UTF-8 Mode" section in Doc/library/os.rst.
* Add warnings to Py_DecodeLocale() and Py_EncodeLocale() docs.
* Document how Python selects the filesystem encoding and error
handler at a single place: PyConfig.filesystem_encoding and
PyConfig.filesystem_errors.
* PyConfig: move orig_argv member at the right place.
- primary change is to add a new default filter entry for
'default::DeprecationWarning:__main__'
- secondary change is an internal one to cope with plain
strings in the warning module's internal filter list
(this avoids the need to create a compiled regex object
early on during interpreter startup)
- assorted documentation updates, including many more
examples of configuring the warnings settings
- additional tests to ensure that both the pure Python and
the C accelerated warnings modules have the expected
default configuration
This module has never been enabled by default, never worked correctly
on x86-64, and caused ABI problems that caused C extension
compatibility. See bpo-29137 for details/discussion.
The default value of __len__ is 0, not 1:
>>> from unittest.mock import MagicMock
>>> mock = MagicMock()
>>> len(mock)
0
Reported by Alex on docs@p.o.
Remove the remaining VMSError reference. VMS support is gone.
This restores details lost in revision 097f4fda61a4 (since Python 3.3,
related to the new OSError subclasses). Further additions:
* Markup for attributes and constructor signature
* Explain "winerror" and "filename2"
* Extend test to check for filename2 defaulting to None
* Clarify that the constructor can return a subclass
I have intentionally left out any details of allowing more than five
arguments, or how the "args" attribute is set for four or more arguments.
These details seem to be dependent on the Python version and platform.
timeout when interrupted by a signal, except if the signal handler raises an
exception. This change is part of the PEP 475.
The asyncore and selectors module doesn't catch the InterruptedError exception
anymore when calling select.select(), since this function should not raise
InterruptedError anymore.