use explicit relative cimports in cython files

[a-andre]

to fix some compile errors when using cython's language_level 3.

Component: python3

Author: André Apitzsch

Branch/Commit: 5ddec3a

Reviewer: Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/22214

[a-andre]

Branch: u/aapitzsch/22214

[a-andre]

Commit: 5ddec3a

[a-andre]

New commits:

5ddec3a

use explicit relative cimport in cython files

[jdemeyer]

comment:2

I think that you should add

from __future__ import absolute_import

to all those files to prevent regressions.

[fchapoton]

comment:3

I agree with Jeroen, please add the future imports.

How did you discover these compiling errors ? Could you please explain ?

[a-andre]

comment:4

Replying to @fchapoton:

I agree with Jeroen, please add the future imports.

How did you discover these compiling errors ? Could you please explain ?

I added 'language_level': 3, to the compiler directives in src/setup.py (about line 405).

[tscrim]

Reviewer: Travis Scrimshaw

[tscrim]

comment:5

Patchbot is (essentially) green, so positive review.

[vbraun]

Changed branch from u/aapitzsch/22214 to 5ddec3a