lazy import module

[robertwb]

This is something I came up with when trying to reduce sage start up time.

2.033 sage.all (None)
0.407 sage.server.all (sage.all)
0.404 notebook.all (sage.server.all)
0.365 sage.server.notebook.notebook (notebook.all)
...

Now notebook() needs to be in the global namespace, but usually the entire notebook server does not need to be loaded. I'm sure there's other trimming we could do here as well.

It's unclear what level to put this in, but I would think sage.server.notebook.all would be a good place (e.g. we could lazily import interact., sage_email., and lazily import notebook and inotebook). That could cut down startup time by 25%.

Component: user interface

Author: Robert Bradshaw

Reviewer: Mitesh Patel

Merged: sage-4.3.2.alpha1

Issue created by migration from https://trac.sagemath.org/ticket/7502

[robertwb]

Attachment: 7502-lazy-import.patch.gz

[qed777]

comment:1

Somewhat related: #8102 + #8107 reduce the startup time by cutting unnecessary imports.

[qed777]

comment:2

By the way, is this up for review?

[robertwb]

comment:3

Yes.

[qed777]

Attachment: 7502-lazy-import.2.patch.gz

Also map tab completion. Add to reference manual. Rebased vs. 4.3.2.alpha0. Replaces previous.

[qed777]

Author: Robert Bradshaw

[qed777]

Reviewer: Mitesh Patel

[qed777]

comment:4

My review is positive, but someone should review the changes in v2.

[robertwb]

comment:5

Thanks. Yes, your additions look good as well.

[sagetrac-mvngu]

Merged: sage-4.3.2.alpha1

[sagetrac-mvngu]

comment:6

Merged 7502-lazy-import.2.patch.