Import from traits apis

[aaronayres35]

With the release of traits 6.2 a section was added to the documentation explicitly requesting users to import from the .api modules in traits. See PR enthought/traits#1387

Motivated by this I decided to run through pyface looking for any non api imports from traits. This PR updates a couple (namely it always imports UnittestTools from the traits.testing.api and ETSConfig from traitst.etsconfig.api.

However, I ran into many more examples of traits imports of things not exposed in traits apis. It is known that this is done but I figured it couldn't hurt to compile a list. It may be fine to leave them as is, some of these we may want to expose in some traits api, some of them we may not want to be pulling from traits (traits isn't meant to be a storage place for miscellaneous utilities). This list probably warrants being in a separate or multiple separate issues which I can gladly open eventually. For now these are the imports I found:

From traits.trait_base there are imports of:

• xgetattr
• xsetattr
• get_resource_path
• user_name_for
• traits_home

Additionally we import optional dependencies from traits.testing.optional_dependencies

From traits.trait_list_object we import TraitsList but this is a different TraitList from the one exposed in traits.api

from traits.version we import version

from traits.util.resource we import get_path

form traitst.trait_notifiers we import set_ui_handler and ui_handler

from traitss.util.clean_strings we import python_name

and from traits.util.camel_case we import camel_case_to_words

[rahulporuri]

This list probably warrants being in a separate or multiple separate issues which I can gladly open eventually. For now these are the imports I found:

I think this warrants an issue on traits - and we can leave it to the traits maintainer to decide which will be exposed via the api module and which won't.

[rahulporuri]

LGTM

[aaronayres35]

This list probably warrants being in a separate or multiple separate issues which I can gladly open eventually. For now these are the imports I found:

I think this warrants an issue on traits - and we can leave it to the traits maintainer to decide which will be exposed via the api module and which won't.

SGTM, I opened enthought/traits#1424