[Python-Dev] Emit SyntaxWarning on unrecognized backslash escapes?

[Ezio Melotti]

Hi,

On Mon, Feb 23, 2015 at 9:58 PM, Joao S. O. Bueno <jsbueno at python.org.br> wrote:
> On 23 February 2015 at 16:47, Antoine Pitrou <solipsis at pitrou.net> wrote:
>> On Mon, 23 Feb 2015 09:29:09 -0800
>> Guido van Rossum <guido at python.org> wrote:
>>> On Mon, Feb 23, 2015 at 9:01 AM, Ethan Furman <ethan at stoneleaf.us> wrote:
>>>
>>> > On 02/23/2015 08:12 AM, Brett Cannon wrote:
>>> > > On Mon Feb 23 2015 at 10:55:23 AM Chris Angelico wrote:
>>> >
>>> > >> Is it at all possible for this to be introduced in the 2.x line [...]
>>> > >
>>> > > Starts with a minor version.
>>> >
>>> > Isn't there a -3 switch or something like that in 2.7.x to trigger
>>> > warnings/errors to help port to 3.x?  Seems like this
>>> > kind of warning could go there.
>>> >
>>>
>>> If we agree it will be a syntax error in 3.x eventually.
>>
>> That sounds frankly like a pedantic change.
>
> The real problem there, even motivating the request, seems to be new
> users in Windows platforms
> using "\" as file path separator.
>
> That happens all the time, and is this use case that should possibly
> be addressed here - maybe
> something as simple as adding a couple of paragraphs to different places
> in the documentation could mitigate the issue. (in contrast to make a
> tons of otherwise valid code
> to become deprecated in a couple releases).
>

Note that in the introduction page of the tutorial[0], there is
already the following snippet:

"""
If you don’t want characters prefaced by \ to be interpreted as
special characters, you can use raw strings by adding an r before the
first quote:

>>>

>>> print('C:\some\name')  # here \n means newline!
C:\some
ame
>>> print(r'C:\some\name')  # note the r before the quote
C:\some\name
""""

Best Regards,
Ezio Melotti

[0]: https://docs.python.org/3/tutorial/introduction.html


>>
>> Regards
>>
>> Antoine.
>>