Give model classes a nice repr again

[sgillies]

Resolves #1379

[sgillies]

For real-world features, the coordinates are likely to make up most of the representation. Showing 20+ can easily overflow displays. One is enough to see where the feature is in space, roughly. 6 would be reprlib's default, but that's still a lot of characters if we're dealing with small scale, projected features.

[sgillies]

Instead of Fiona 1.8's GeoJSON representation, I propose this. It shows which classes are involved, which is nice. And in a form that could be used to reproduce the objects, modulo the coordinates truncation.

[sgillies]

@loicdtx @mwtoews what do you think of this?

[mwtoews]

Useful reprs are welcome! (And reprlib has evaded my attention!)

As a suggestion, you could code less by adding this once to Object around L179:

    def __repr__(self):
        kvs = [f"{k}={v!r}" for k, v in self.items()]
        return "{}({})".format(self.__class__.__name__, ", ".join(kvs))

but keep Geometry.__repr__ for the _coord_repr difference.

Also also suggest to see the repr class name with the shorter Geometry rather than fiona.Geometry. A counterpoint to this suggestion is that it may confuse users with other library object names also called "Geometry" (I actually can't name any right now, but certainly they exist).

[sgillies]

@mwtoews thank you! I'd like to keep the fiona package name in there for the sake of disambiguation, thinking that in some cases the people that see these will not have intentionally imported fiona, but are getting it second-hand.

As to moving the use of reprlib.repr() to the base class, I found that it, by default, shortens representations too much. I'm finding it useful for shortening representation of geometry coordinates. It might be useful for shortening very long mappings of properties... I'll try that out.

[mwtoews]

@sgillies it's fine to keep fiona. in the repr, so my suggestion would only need to adjust with return "fiona.{}({})".format(self.__class__.__name__, ", ".join(kvs)).

As for shortening other instances of Object, I wasn't suggesting this. But I suppose there could be instances of datasets with many fields or with individual fields with "large" blobs or text attributes.

[sgillies]

@mwtoews thank you for the suggestions!

[loicdtx]

Thanks @sgillies , that's definitely an improvement. I tested it on tests/data/gre.shp and it looks great overall. Two minor observations:

• pprint doesn't work unless coerced to dict (not saying it should work, just pointing it out)
• dict coercion only happens on top level, so that pprint(dict(feature)) does not pprint the properties (that's probably another "issue" though)

>>> import fiona
>>> from pprint import pprint
>>> fc = fiona.open('tests/data/gre.shp')
>>> fc[0]
fiona.Feature(geometry=fiona.Geometry(coordinates=[[(-61.173214300000005, 12.516654800000001), ...]], type='Polygon'), id='0', properties=fiona.Properties(flag='http://upload.wikimedia.org/wikipedia/commons/b/bc/Flag_of_Grenada.svg', name='Grenada', name_cs='Grenada', name_de='Grenada', name_en='Grenada', name_eo='Grenado', name_fr='Grenade', name_fy='Grenada', name_hr='Grenada', name_nl='Grenada', name_ru='Гренада', name_sl='Grenada', name_ta='கிரெனடா', name_uk='Гренада', boundary='administrative', name_tzl='Grenada', timezone='America/Grenada', wikidata='Q769', ISO3166-1='GD', wikipedia='en:Grenada', admin_leve='2', is_in_cont='North America', ISO3166-1_='GD', ISO3166-_1='GRD', ISO3166-_2='308'))

>>> pprint(fc[0])
fiona.Feature(geometry=fiona.Geometry(coordinates=[[(-61.173214300000005, 12.516654800000001), ...]], type='Polygon'), id='0', properties=fiona.Properties(flag='http://upload.wikimedia.org/wikipedia/commons/b/bc/Flag_of_Grenada.svg', name='Grenada', name_cs='Grenada', name_de='Grenada', name_en='Grenada', name_eo='Grenado', name_fr='Grenade', name_fy='Grenada', name_hr='Grenada', name_nl='Grenada', name_ru='Гренада', name_sl='Grenada', name_ta='கிரெனடா', name_uk='Гренада', boundary='administrative', name_tzl='Grenada', timezone='America/Grenada', wikidata='Q769', ISO3166-1='GD', wikipedia='en:Grenada', admin_leve='2', is_in_cont='North America', ISO3166-1_='GD', ISO3166-_1='GRD', ISO3166-_2='308'))

>>> pprint(dict(fc[0]['properties']))
{'ISO3166-1': 'GD',
 'ISO3166-1_': 'GD',
 'ISO3166-_1': 'GRD',
 'ISO3166-_2': '308',
 'admin_leve': '2',
 'boundary': 'administrative',
 'flag': 'http://upload.wikimedia.org/wikipedia/commons/b/bc/Flag_of_Grenada.svg',
 'is_in_cont': 'North America',
 'name': 'Grenada',
 'name_cs': 'Grenada',
 'name_de': 'Grenada',
 'name_en': 'Grenada',
 'name_eo': 'Grenado',
 'name_fr': 'Grenade',
 'name_fy': 'Grenada',
 'name_hr': 'Grenada',
 'name_nl': 'Grenada',
 'name_ru': 'Гренада',
 'name_sl': 'Grenada',
 'name_ta': 'கிரெனடா',
 'name_tzl': 'Grenada',
 'name_uk': 'Гренада',
 'timezone': 'America/Grenada',
 'wikidata': 'Q769',
 'wikipedia': 'en:Grenada'}

>>> pprint(dict(fc[0]))
{'geometry': fiona.Geometry(coordinates=[[(-61.173214300000005, 12.516654800000001), ...]], type='Polygon'),
 'id': '0',
 'properties': fiona.Properties(flag='http://upload.wikimedia.org/wikipedia/commons/b/bc/Flag_of_Grenada.svg', name='Grenada', name_cs='Grenada', name_de='Grenada', name_en='Grenada', name_eo='Grenado', name_fr='Grenade', name_fy='Grenada', name_hr='Grenada', name_nl='Grenada', name_ru='Гренада', name_sl='Grenada', name_ta='கிரெனடா', name_uk='Гренада', boundary='administrative', name_tzl='Grenada', timezone='America/Grenada', wikidata='Q769', ISO3166-1='GD', wikipedia='en:Grenada', admin_leve='2', is_in_cont='North America', ISO3166-1_='GD', ISO3166-_1='GRD', ISO3166-_2='308')}

[sgillies]

@loicdtx thank you for pointing out the issue with dict(). I've addressed that in the latest commits, you'll now get dicts all the way down.