[Python-Dev] Raw string syntax inconsistency (original) (raw)

Nick Coghlan ncoghlan at gmail.com
Mon Jun 18 08:31:54 CEST 2012

On Mon, Jun 18, 2012 at 3:59 PM, "Martin v. Löwis" <martin at v.loewis.de> wrote:

On 17.06.2012 22:41, Guido van Rossum wrote:

Would it make sense to detect and reject these in 3.3 if the 2.7 syntax is used? Maybe we are talking about different things: The (new) proposal is that the ur prefix in 3.3 is a syntax error (again, as it was before PEP 414). So, yes: the raw unicode literals will be rejected (not by explicitly detecting them, though).

I think GvR was replying to my email where I was briefly reconsidering the idea of keeping them around (because the unicode_literals future import already suffers from this problem of literals that don't mean the same things in 2.x and in 3.x). However, that was flawed reasoning on my part - simply banning them altogether in 3.x is the simplest option to ensure this particular error doesn't pass silently, especially since there are alternate forward compatible ways to write them, such as:

Python 2.7.3 (default, May 29 2012, 14:54:22)

from future import unicodeliterals print(u"\u03b3" r"\n") γ\n print(u"\u03b3\n") γ\n

Python 3.3.0a4 (default:f1dd70bfb4c5, May 31 2012, 09:47:51)

print(u"\u03b3" r"\n") γ\n print(u"\u03b3\n") γ\n

Cheers, Nick.

-- Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia

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