Remove spaces in `extras_require`

[cancan101]

Right now the extras_require is:

          extras_require = {
            'Additional image formats' : ["itk >= 3.16.0"]
          },

which contains a space in the key, something I have never seen before. This causes problems when trying to pip install. Perhaps there is a way to escape, but this seems non intuitive:

$ pip install "medpy[Additional image formats]"
...
pip._vendor.packaging.requirements.InvalidRequirement: Invalid requirement, parse error at "'[Additio'"

I suggest offering a string without a space.

[loli]

Apparently, using spaces in dictionary keys is absolutely valid, as discussed in https://stackoverflow.com/questions/13474957/spaces-in-python-dictionary-keys. But I can see your point that it becomes inconvenient in this case.

On the other hand, the itk package can't be installed via pip. Please see the documentation (https://loli.github.io/medpy/) for detailed instructions on how to compile ITK with Python wrappers.

[cancan101]

I wasn't referring to spaces in dictionary keys in general, I was specifically referring to extra requires. Also I think there is now a wheel for itk so I think It can be pip installed.

[loli]

You're right, that's amazing. Thank you for pointing this out to me!

https://blog.kitware.com/itk-is-on-pypi-pip-install-itk-is-here/

Did you already tried if the medpy IO with that version of ITK?

[cancan101]

Ok given that people probably were not using that extra (and that It didn't work until recently) what do you think about renaming it to all or extra_formats or itk?

[loli]

I would go with extra_formats, since that's the sole purpose of the itk module in MedPy. If you want, you can make the adjustment and create a pull request. Otherwise I'll fix it when I get around to it.