Add a space group string representation, tested

[hakonanes]

Signed-off-by: Håkon Wiik Ånes hwaanes@gmail.com

Hi!

I'm one of the developers of the orix Python package (https://github.com/pyxem/orix) for handling crystal orientation mapping data. We're depending on diffpy.structure for storage and handling of unit cell information in our Phase object, and will soon add a space group attribute via your SpaceGroup class to it. It would therefore be nice to have a string representation of SpaceGroup, hence this PR.

Result of this PR:

>>> from diffpy.structure.spacegroupmod import GetSpaceGroup
# Before
>>> print(GetSpaceGroup(229))
<diffpy.structure.spacegroupmod.SpaceGroup object at 0x7f819481a490>
# After
>>> print(GetSpaceGroup(229))
SpaceGroup #229 (Im-3m, Cubic). Symmetry matrices: 96, point sym. matr.: 48

Added:

• a one-line SpaceGroup.__repr__() detailing space group number, short name, crystal system, number of symmetry matrices and number of point group symmetry matrices
• a naive test for this method
• the PyCharm project directory .idea and the htmlcov directory returned by $ coverage html to .gitignore

Tests pass with Python 3.7 and Python 2.7 from Anaconda.

I'll be happy to shorten the string if you find it too long, or change it if you prefer another representation.

[codecov]

Codecov Report

Merging #45 into master will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master      #45      +/-   ##
==========================================
+ Coverage   95.11%   95.12%   +0.01%     
==========================================
  Files          44       44              
  Lines        5203     5214      +11     
==========================================
+ Hits         4949     4960      +11     
  Misses        254      254              

Impacted Files	Coverage Δ
src/diffpy/structure/spacegroupmod.py	92.08% <100.00%> (+0.11%)	⬆️
src/diffpy/structure/tests/testspacegroups.py	100.00% <100.00%> (ø)

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[sbillinge]

@hakonanes code looks good. I would like to capture this into docs/changelog if possible. @pavoljuhas is that done automatically here using commit messages (changelog) and scraping docstrings (docs)? We are behind with docs in general, but may as well handle this as well as we can moving forward...

[pavoljuhas]

Hi Håkon, Thank you for your contribution. Please remove the change to .gitignore, it should not be mixed up with changes to actual functionality. (You can rebase with the fixup commit I added).

I have also added an empty new section to the CHANGELOG.md.
Can you please add a one-line description of this feature?

[pavoljuhas]

I have noticed one more issue in the test, please correct.
Otherwise LGTM, thank you for contributing.

[pavoljuhas]

@pavoljuhas is that done automatically here using commit messages (changelog) and scraping docstrings (docs)?

No, changelog needs to be updated manually. It is intended for users and should be easy to digest, it would be too noisy if generated from commit strings.

[pavoljuhas]

Merged as fe4b46b. Thank you!

[hakonanes]

Great, I hope other orix developers and I can contribute more in the future. Thank you!

[sbillinge]

Thank you so much Hakon, we really appreciate it!

…

On Tue, Jul 28, 2020 at 7:06 AM Håkon Wiik Ånes ***@***.***> wrote: Great, I hope other orix developers and I can contribute more in the future. Thank you! — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#45 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABAOWUKNRMIWZ7QW3RGRHCTR52WMPANCNFSM4PFRKENQ> .

-- Professor Simon Billinge Columbia University