Replace use of sage.misc.package.PackageNotFoundError (2); lazy_import: Add keyword argument 'feature'

[mkoeppe]

This helps with the modularization of sagelib.

We demonstrate its use by simplifying:

• sage.groups.braid (which depends on the optional library libbraiding via sage.libs.libbraiding). Actually a standard package
• sage.sat.solvers.cryptominisat, .picosat
• sage.matrix.matrix_space (meataxe)
• sage.graphs.graph (tdlib, mcqd)

This simplification helps eliminate the use of sage.misc.package.PackageNotFoundError. See #30607.

CC: @kiwifb @jhpalmieri @slel @seblabbe @dcoudert

Component: refactoring

Author: Matthias Koeppe

Branch: e1f6624

Reviewer: David Coudert

Issue created by migration from https://trac.sagemath.org/ticket/30616

[mkoeppe]

Branch: u/mkoeppe/lazy_import__add_keyword_argument__feature_

[sagetrac-git]

Commit: 30613c8

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

fdc62f7	src/sage/sat/solvers/cryptominisat.py: Use lazy_import with feature instead of try/except
30613c8	src/sage/sat/solvers/picosat.py: Use lazy_import with feature instead of try/except

[mkoeppe]

Author: Matthias Koeppe

[sagetrac-git]

Changed commit from 30613c8 to e1f6624

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

f2b5a1c	Graph.treewidth: Fix up logic in algorithm selection
e1f6624	Graph.{treewidth,clique_maximum,clique_number}: Use features instead of sage.misc.package.PackageNotFoundError

[dcoudert]

comment:8

I tried before and after installing tdlib, mcqd, cryptominisat, pycosat (not obvious to know that its picosat), meataxe. Note that libbraiding was already installed (is it standard now ?). It's working well.

However, we have several pyflakes errors (see patchbot)

src/sage/graphs/graph.py:6419:20 undefined name 'mcqd'
src/sage/graphs/graph.py:6517:24 undefined name 'mcqd'

src/sage/groups/braid.py:82:1 'sage.misc.package.PackageNotFoundError' imported but unused
src/sage/groups/braid.py:1080:13 undefined name 'rightnormalform'
src/sage/groups/braid.py:1096:13 undefined name 'centralizer'
src/sage/groups/braid.py:1115:13 undefined name 'supersummitset'
src/sage/groups/braid.py:1138:13 undefined name 'greatestcommondivisor'
src/sage/groups/braid.py:1158:13 undefined name 'leastcommonmultiple'
src/sage/groups/braid.py:1183:13 undefined name 'conjugatingbraid'
src/sage/groups/braid.py:1208:13 undefined name 'conjugatingbraid'
src/sage/groups/braid.py:1236:15 undefined name 'ultrasummitset'
src/sage/groups/braid.py:1261:16 undefined name 'thurston_type'
src/sage/groups/braid.py:1326:24 undefined name 'rigidity'
src/sage/groups/braid.py:1358:15 undefined name 'sliding_circuits'

src/sage/matrix/matrix_space.py:287:24 undefined name 'Matrix_gfpn_dense'

src/sage/sat/solvers/cryptominisat.py:72:24 undefined name 'Solver'

src/sage/sat/solvers/picosat.py:63:23 undefined name 'solve'

[slel]

comment:9

Replying to @dcoudert:

Note that libbraiding was already installed (is it standard now ?).

Yes, see build/pkgs/libbraiding/type which you can either
check with this command:

$ cat build/pkgs/libbraiding/type
standard

or by viewing that file online:

• https://github.com/sagemath/sage-prod/blob/develop/build/pkgs/libbraiding/type

This happened in

• Make libhomfly and libbraiding standard packages. #25705 Make libhomfly and libbraiding standard packages

which was merged in Sage 8.4.beta0.

[dcoudert]

comment:10

Thanks.

Can we do something for the pyflakes issues or is it the prize to pay for lazy import ?

[mkoeppe]

comment:11

Unfortunately that's the prize to pay...

[dcoudert]

Reviewer: David Coudert

[dcoudert]

comment:12

So then.

[mkoeppe]

comment:13

Thank you!

[mkoeppe]

comment:14

Replying to @mkoeppe:

Unfortunately that's the price to pay...

Follow-up: #30647 - Make lazy_import more friendly to pyflakes and other static checkers

[vbraun]

Changed branch from u/mkoeppe/lazy_import__add_keyword_argument__feature_ to e1f6624

[kliem]

comment:16

I'm going to add the missing documentation on #30587.

[kliem]

Changed commit from e1f6624 to none