small problems with CHomP, followup to #15161

[jhpalmieri]

This is a followup to #15161, fixing some problems which arose from the changes there. In particular, if CHomP was installed, then the changes at #15161 led to some doctest failures. These have mostly been corrected, except for failures as in #12607 and also that CHomP seems to be broken on my machine, so it is not computing homology groups correctly. I think we should put off actually fixing CHomP to #15202.

Component: algebraic topology

Author: John Palmieri

Branch/Commit: u/jhpalmieri/chain @ b02b283

Reviewer: Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/15730

[tscrim]

comment:3

LGTM. Just to note, I'm getting two errors, which weren't there before I installed the CHomP spkg, but the first is noted in #12607:

sage -t chain_complex.py
**********************************************************************
File "chain_complex.py", line 1135, in sage.homology.chain_complex.ChainComplex_class.homology
Failed example:
    D.homology()
Expected:
    {0: 0, 1: 0, 4: 0, 5: 0}
Got:
    {}
**********************************************************************
File "chain_complex.py", line 1397, in sage.homology.chain_complex.ChainComplex_class.torsion_list
Failed example:
    C.torsion_list(5)
Expected:
    [(2, [1]), (3, [3])]
Got:
    [(2, []), (3, [])]
**********************************************************************

[tscrim]

Reviewer: Travis Scrimshaw