Fix "invalid escape sequence" when building the doc

[fbissey]

While building the doc there are messages of the kind

/dev/shm/portage/sci-mathematics/sage-9999/work/sage-9999/src-python3_7/build/lib/sage/rings/quotient_ring.py:1355: DeprecationWarning: invalid escape sequence \Q
[dynamics ] <unknown>:1355: DeprecationWarning: invalid escape sequence \Q
[algebras ] <unknown>:1355: DeprecationWarning: invalid escape sequence \Q
/dev/shm/portage/sci-mathematics/sage-9999/work/sage-9999/src-python3_7/build/lib/sage/rings/function_field/ideal.py:2218: DeprecationWarning: invalid escape sequence \g
[function_] <unknown>:2218: DeprecationWarning: invalid escape sequence \g
[rings    ] <unknown>:1355: DeprecationWarning: invalid escape sequence \Q
[schemes  ] <unknown>:1355: DeprecationWarning: invalid escape sequence \Q
[dynamics ] <unknown>:1355: DeprecationWarning: invalid escape sequence \Q
[algebras ] <unknown>:1355: DeprecationWarning: invalid escape sequence \Q
[function_] <unknown>:2218: DeprecationWarning: invalid escape sequence \g
[rings    ] <unknown>:1355: DeprecationWarning: invalid escape sequence \Q
[schemes  ] <unknown>:1355: DeprecationWarning: invalid escape sequence \Q

It is apparently caused by jinja and python 3.6+. The guilty escape sequences should be put in raw strings. See ​https://stackoverflow.com/questions/50504500/deprecationwarning-invalid-escape-sequence-what-to-use-instead-of-d

[fbissey]

I remember discussing it in a previous sphinx (1.8) ticket. We had those all over the place. They seem to have reduced. The branch tckle the two I still see in sage-on-gentoo but there could be other masked by one of my patches.

---

New commits:

​8f6e482

fix some invalid escape sequence messages

[jhpalmieri]

There are others, but I don't think they come from the Sage library:

[repl     ] <unknown>:181: DeprecationWarning: invalid escape sequence \)
[repl     ] <unknown>:365: DeprecationWarning: invalid escape sequence \w

Is this ready for review? If so, feel free to give it a positive review from me.

[fbissey]

Replying to jhpalmieri:

There are others, but I don't think they come from the Sage library:

[repl     ] <unknown>:181: DeprecationWarning: invalid escape sequence \)
[repl     ] <unknown>:365: DeprecationWarning: invalid escape sequence \w

Is this ready for review? If so, feel free to give it a positive review from me.

Those are funny. I see them in vanilla sage but not in sage-on-gentoo. It would be nice to figure them out one day. All I could see under repl was already properly made into a raw string.

If you don't have any more clue about it I guess we should already go with the one that are fixed here.

[jhpalmieri]

Replying to fbissey:

Replying to jhpalmieri:

There are others, but I don't think they come from the Sage library:

[repl     ] <unknown>:181: DeprecationWarning: invalid escape sequence \)
[repl     ] <unknown>:365: DeprecationWarning: invalid escape sequence \w

Is this ready for review? If so, feel free to give it a positive review from me.

Those are funny. I see them in vanilla sage but not in sage-on-gentoo. It would be nice to figure them out one day. All I could see under repl was already properly made into a raw string.

If you don't have any more clue about it I guess we should already go with the one that are fixed here.

I think they come from IPython, so upgrading that should help: ​https://trac.sagemath.org/ticket/28550#comment:2

[fbissey]

I am on ipython-7.5 in sage-on-gentoo, that would explain why I don't see them there. I completely missed that ticket.