A new AiiDA release v1.2.0 is available! You can find more information at our download page. It can be installed through pip as:
pip install aiida-core==1.2.0
reentry scan
N.B.: the `reentry scan` step is crucial as we have added new entry points.
This is the second minor version of the v1 series and comes with mostly new features.
Especially groups have received a lot of new functionality.
Groups can now be subclassed
The `Group` class can now be subclassed to implement custom functionality, just like for example the `Data` node class. They can be registered through entry points in the new entry point category “aiida.groups”. Please refer to the documentation [1] for more details.
Virtual group hierarchy through `GroupPath`
The group concept in AiiDA so far has been “flat”. That is to say, group can contain nodes, but you a group cannot contain another group. Many users have expressed the wish to be able to treat groups a bit more like folders on a filesystem and add some hierarchy to them. Thanks to a contribution by Chris Sewell, the `GroupPath` utility now provides a virtual hierarchy based on the group labels. Forward slash characters ‘/’ in group labels will be interpreted as sub groups. A very short demonstration:
In [1]: from aiida.tools.groups import GroupPath
...: Group(label='project/sub/a')
...: Group(label='project/sub/b')
In [2]: path = GroupPath('project/sub')
...: for child in path.children:
...: group = child.get_group()
...: print('Group<{}> contains {} nodes'.format(group.label, group.count()))
...:
Group<project/sub/a> contains 0 nodes
Group<project/sub/b> contains 0 nodes
Of course the `GroupPath` class provides much more than that and it is also exposed on the CLI through `verdi group path ls`. Extensive documentation of all functionality will be added to the official documentation soon.