Added ArrayImage to pyface.api as per #972

[Palash-Vishnani]

No description provided.

[Palash-Vishnani]

@corranwebster @rahulporuri checkout this PR.

[rahulporuri]

This PR is almost ready. Apart from the comment below, can you also add ArrayImage to the module docstring at the top of the file? ArrayImage can be included in the "Miscellaneous" section.

[rahulporuri]

The imports are sorted alphabetically in this file so can you please update the location of this import statement?

[Palash-Vishnani]

@rahulporuri It's fine now right??

[corranwebster]

There's a technical gotcha in this which I think @rahulporuri is the person to make a decision. Currently I think that NumPy is technically an optional dependency of Pyface with the Qt backend (it is required for Wx for various historical reasons). This change means the NumPy is required when importing pyface.api. For that reason, we should guard the import in the same way as the pieces which depend on Pygments:

pyface/pyface/api.py

Lines 118 to 123 in 997c78f

	# Excuse pygments dependency (for Qt), otherwise re-raise
	with _optional_import(
	"pygments",
	msg="PythonEditor not available due to missing pygments.",
	logger=_logging.getLogger(__name__)):
	from .python_editor import PythonEditor

but with numpy in the place of Pygments.

Alternatively @rahulporuri may say that depending on numpy is fine, but in that case we need to update the requirements here:

pyface/pyface/__init__.py

Lines 21 to 27 in 997c78f

	__requires__ = [
	'importlib-metadata>=3.6.0; python_version<"3.8"',
	'importlib-resources>=1.1.0; python_version<"3.9"',
	"traits>=6.2"
	]
	__extras_require__ = {
	"wx": ["wxpython>=4", "numpy"],

This is why I didn't put ArrayImage in the API module during the recent PR.

[Palash-Vishnani]

@corranwebster @rahulporuri Soo what to do with this PR now? Do I need to do more modifications in it, or will it be merged after some time?

[rahulporuri]

@Palash-Vishnani sorry for the delayed response but @corranwebster is right. I missed it when i first reviewed this PR. Can you make the changes that corran recommended i.e. something like this

 # Excuse pygments dependency (for Qt), otherwise re-raise 
 with _optional_import( 
         "numpy", 
         msg="ArrayImage not available due to missing numpy.", 
         logger=_logging.getLogger(__name__)): 
     from .array_image import ArrayImage

Can you please add this new import next to the other optional imports?

[Palash-Vishnani]

@rahulporuri I'll do it but should I remove this import satement from .array_image import ArrayImage from the file? And also do I need to write this statement in the Miscellaneous section of module docstrings:

"Note that the :class:~.ArrayImage is
only available if the numpy package is available in the Python
environment."

[rahulporuri]

@rahulporuri I'll do it but should I remove this import satement from .array_image import ArrayImage from the file?

Yes. You need to replace the from .array_image import ArrayImage with the new with _optional_import(...): code.

And also do I need to write this statement in the Miscellaneous section of module docstrings: "Note that the :class:~.ArrayImage is only available if the numpy package is available in the Python environment."

Yes please. That's right. You need to add this information in the module docstring to make it clear to end users.

[rahulporuri]

LGTM. Merging now.

[rahulporuri]

Thanks @Palash-Vishnani for the contribution!

If you're interested in doing more, you can also add the PILImage class to pyface.api. The changes there will almost be the same as this PR - except PILImage depends on the pillow python library so you need to use with _optional_import("pillow", ...). With that PR, we will be able to close the issue #972.