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Author abarry
Recipients abarry, ezio.melotti, vstinner
Date 2016-06-21.20:34:18
SpamBayes Score -1.0
Marked as misclassified Yes
Message-id <>
Attached patch deprecates invalid escape sequences in unicode strings. The point of this is to prevent issues such as #27356 (and possibly other similar ones) in the future.

Without the patch:

>>> "hello \world"
'hello \\world'

With the patch:

>>> "hello \world"
DeprecationWarning: invalid escape sequence 'w'

I'll need some help (patch isn't mergeable yet):

test_doctest fails on my machine with the patch (and -W), and I don't know how to fix it. test_ast fails an assertion (!PyErr_Occurred() in PyObject_Call in abstract.c) when -W is on, and I also don't know how to fix it (I don't even know what causes it).

Of course, I went ahead and fixed all instances of invalid escape sequences in the stdlib (that I could find) so that no DeprecationWarning is encountered.

Lastly, I thought about also doing this to bytes, but I ran into some issues with some invalid escapes such as \u, and _codecs.escape_decode would trigger the warning when passed br"\8" (for example). Ultimately, I decided to leave bytes alone for now, since it's mostly on the lower-level side of things. If there's interest I can add it back.
Date User Action Args
2016-06-21 20:34:22abarrysetrecipients: + abarry, vstinner, ezio.melotti
2016-06-21 20:34:20abarrysetmessageid: <>
2016-06-21 20:34:19abarrylinkissue27364 messages
2016-06-21 20:34:19abarrycreate