Issue 15096: Drop support for the "ur" string prefix (original) (raw)
Created on 2012-06-17 12:17 by ncoghlan, last changed 2022-04-11 14:57 by admin. This issue is now closed.
Messages (8)
Author: Alyssa Coghlan (ncoghlan) * 
Date: 2012-06-17 12:17
When PEP 414 restored support for explicit Unicode literals in Python 3, the "ur" string prefix was deemed to be a synonym for the "r" prefix.
However, "ur" in 2.x was only kinda-sorta-raw, since it still supported Unicode escapes:
$ python Python 2.7.3 (default, Apr 30 2012, 21🔞11) [GCC 4.7.0 20120416 (Red Hat 4.7.0-2)] on linux2 Type "help", "copyright", "credits" or "license" for more information.
print(ur'\u03B3') γ
By contrast, they really are raw strings in 3.x, because the default UTF-8 source code encoding allows arbitrary Unicode characters to be included directly in the literal:
$ ./python Python 3.3.0a4+ (default:cfbf6aa5c9e3+, Jun 17 2012, 15:25:45) [GCC 4.7.0 20120507 (Red Hat 4.7.0-5)] on linux Type "help", "copyright", "credits" or "license" for more information.
r"γ" 'γ' "\U000003B3" 'γ' r"\U000003B3" '\U000003B3' ur"\U000003B3" '\U000003B3'
Rather than reintroducing this weird legacy not-really-raw string behaviour, I'd prefer to revert this aspect of the PEP 414 changes completely.
Author: Christian Heimes (christian.heimes) *
Date: 2012-06-17 12:58
+1
Raw unicode strings are rarely used and it's easy to overcome the limitation. I've created a patch that disabled ur'' syntax, updates the docs and adds some tests for u'' syntax.
I couldn't find any tests for the syntax ... shame on you! :)
Author: Serhiy Storchaka (serhiy.storchaka) *
Date: 2012-06-17 16:36
I've created a patch that disabled ur'' syntax, updates the docs and adds some tests for u'' syntax.
Don't forget tokenize module (see ).
Author: Georg Brandl (georg.brandl) *
Date: 2012-06-19 20:17
If you commit this, please do so before beta1.
Author: Christian Heimes (christian.heimes) *
Date: 2012-06-19 20:52
I'll submit an updated patch tomorrow.
Author: Christian Heimes (christian.heimes) *
Date: 2012-06-19 21:43
New patch:
corrected comment in Parser/tokenizer.c
added test for ub"" and bu"" raising SyntaxError
removed handling of ur"" from tokenize module
Serhiy, could you please review my changed to the tokenize module? I think I found all relevant places but I'm not absolutely sure.
Author: Roundup Robot (python-dev) 
Date: 2012-06-20 09:18
New changeset 8e47e9af826e by Christian Heimes in branch 'default': Issue #15096: Drop support for the ur string prefix http://hg.python.org/cpython/rev/8e47e9af826e
Author: Christian Heimes (christian.heimes) *
Date: 2012-06-20 09:24
Thanks for you review, Serhiy. I removed the last remains from test_tokenize and even found another missing sentence in the docs.
History
Date
User
Action
Args
2022-04-11 14:57:31
admin
set
github: 59301
2014-09-02 20:59:57
r.david.murray
link
2012-06-20 09:24:48
christian.heimes
set
status: open -> closed
resolution: fixed
messages: +
stage: patch review -> resolved
2012-06-20 09🔞14
python-dev
set
nosy: + python-dev
messages: +
2012-06-19 21:43:43
christian.heimes
set
keywords: + needs review
files: + issue15096-2.patch
messages: +
stage: needs patch -> patch review
2012-06-19 20:52:39
christian.heimes
set
assignee: christian.heimes
messages: +
2012-06-19 20:17:14
georg.brandl
set
nosy: + georg.brandl
messages: +
2012-06-19 16:19:25
vinay.sajip
link
2012-06-18 19:24:30
Arfrever
set
nosy: + Arfrever
2012-06-17 16:36:03
serhiy.storchaka
set
messages: +
2012-06-17 16:20:34
flox
set
nosy: + vinay.sajip
2012-06-17 16:16:16
flox
set
2012-06-17 12:58:52
christian.heimes
set
files: + issue15096-1.patch
nosy: + christian.heimes
messages: +
keywords: + patch
2012-06-17 12:30:41
serhiy.storchaka
set
nosy: + serhiy.storchaka
2012-06-17 12:20:29
ezio.melotti
set
nosy: + ezio.melotti
2012-06-17 12🔞03
ncoghlan
set
priority: normal -> release blocker
2012-06-17 12:17:38
ncoghlan
create