python3 report (may of the last python2 year)

[Frédéric Chapoton]

Hello,

Once again, I suggest that all developers should switch to python3 right now.

sage-with-python3 (version 8.8.beta6, using python 3.7.3) has now less than 50 files (49 precisely) with failing doctests, for a total of 151 failing doctests. Among these, 20 files have a single failing doctest.

A detailed summary can be found here : https://trac.sagemath.org/ticket/26212

There still remains many hard-to-fix issues. Please help if you can.

* Matroids need quite a lot of care. It would be great if the authors of this code could take up the task. No progress since the last call.

* combinat people should also care for their code, in particular about crystals.

* We should still strive to make all tests pass in rings/ and in particular for polynomials. Any volunteer to handle integer.pyx ?

* src/sage/misc/nested_class.pyx should be fixed (this was almost done, but stopped)

* There are some remaining hard problems in graphs, under current scrutiny I think.

* Some annoying failures in the French book, not all related to graphs.

I have no idea how long it will take to fix all that. Then we will have to fix all optional packages..

Frédéric

[David Coudert]

* There are some remaining hard problems in graphs, under current scrutiny I think.

The main remaining issues in the graph module are related to isomorphisms, automorphisms, and related methods.

1) #27571: align behaviors of algorithm 'sage' and 'bliss' in `automorphism_group` and fix a doctest in MathonPseudocyclicStronglyRegularGraph generator.

When finalized, we will have to fix bugs with `automorphism_group`, `PermutationGroupElement`, and possibly other methods.

2) fix `is_isomorphic` for graphs with edge labels.

A first attempt is done in #27232, but this proposal is certainly not satisfactory. One issue is that we can sort lists of unhashable objects (of different types).

3) #27435 deal with a failing doctest in graph_database.py with interactive_query 

Help is more than welcome !!

David.