Replace some deprecated python functions in sage/algebras

[aapitzsch]

We should prepare moving to Python3.

Execute

2to3 -f has_key -f except -f idioms -f ne -f raise

for each *.py in sage/algebras.

See ​http://docs.python.org/library/2to3.html#fixers for meaning of the parameters.

---

Apply trac_12461.patch​ and trac_12461_2b.patch​ to the Sage library repository.

[davidloeffler]

This conflicts with #12484 (merged in 5.0.beta5) -- can you rebase it?

[aapitzsch]

Rebased.

[davidloeffler]

I've added #12484 as a dependency (since there is a copy of the patchbot still running against 4.8)

[davidloeffler]

I don't like the change at line 148 of free_algebra_quotient:

 	148	        return isinstance(self, type(right)) and \ 
149	149	               self.ngens() == right.ngens() and \ 
150	150	               self.rank() == right.rank() and \ 
151	151	               self.module() == right.module() and \ 

If type(right) was some very generic base class like SageObject, then the first statement would be True, but the remaining ones would be completely meaningless, so you'd get weird errors being raised. It should probably be isinstance(other, FreeAlgebraQuotient) or something like that.

That is my only disagreement with this patch, so if you can do a tiny fix for that I'll happily give it a positive review.

[aapitzsch]

Apply after trac_12461.patch

[aapitzsch]

Replying to davidloeffler:

If type(right) was some very generic base class like SageObject, then the first statement would be True, but the remaining ones would be completely meaningless, so you'd get weird errors being raised. It should probably be isinstance(other, FreeAlgebraQuotient) or something like that.

You are right. I couldn't think of another possible type, so I used FreeAlgebraQuotient.

[davidloeffler]

The double colon after EXAMPLES that your new patch adds shouldn't be there, and it causes an error in building the docs:

/storage/masiao/sage-5.0.beta7-patchbot/local/lib/python2.7/site-packages/sage/algebras/free_algebra_quotient.py:docstring of sage.algebras.free_algebra_quotient.FreeAlgebraQuotient:10: WARNING: Literal block expected; none found.

[davidloeffler]

apply over trac_12461.patch

[davidloeffler]

Here's a strict subset of your patch (literally obtained by deleting one of the two hunks from your patch in a text editor). If you're happy with that, you can set this to positive review.

[jdemeyer]

Please clarify which patches have to be added.

[aapitzsch]

Add

1. trac_12461.patch
2. trac_12461_2b.patch