Bug with the URI parameter

[Mymoza]

From the provided Jupyter Notebook to get started with Pyannote-metrics, it was throwing an error when running the whole notebook as is for this line:

diarizationErrorRate(reference, hypothesis, detailed=True, uem=Segment(0, 40))

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-58-445b485ca05e> in <module>
----> 1 diarizationErrorRate(reference, hypothesis, detailed=True, uem=Segment(0, 40))

/srv/conda/envs/notebook/lib/python3.7/site-packages/pyannote/metrics/base.py in __call__(self, reference, hypothesis, detailed, **kwargs)
    129         else:
    130             self.uris_[uri] += 1
--> 131             uri = uri + ' #{0:d}'.format(self.uris_[uri])
    132 
    133         self.results_.append((uri, components))

TypeError: unsupported operand type(s) for +: 'NoneType' and 'str'

The uri parameter is used to remember which document it describes, it's optional. As it was empty in the Notebook, it throws an error to concatenate NoneType + str.

This PR changes the + operand for , so that the uri parameter can be None.

I tested this PR with pip install git+https://git@github.com/Mymoza/pyannote-metrics.git@mpgill-uri-bug and it works well now:

{'confusion': 7.0,
 'correct': 22.0,
 'diarization error rate': 0.5161290322580645,
 'false alarm': 7.0,
 'missed detection': 2.0,
 'total': 31.0}

[hbredin]

Thanks @Mymoza . I will have a closer look at this next week.

[hbredin]

I finally had the chance to look at your PR.

I'd rather keep uri a string rather than making it a tuple (as this might otherwise have some unexpected consequences).

Therefore, I propose we solve the issue differently. I would replace line 126 by something like

uri = reference.uri
if uri is None:
   uri = "(None)" 

... and leave the rest unchanged. Can you check that this solves the issue and update your PR accordingly?

Also please use develop branch as your base branch in the PR.

[hbredin]

Fixed in commit d9ca221