GeoJSON feature ID creator fails when properties contain list/dict

This code throws a TypeError: (edit: add geometry type to feature)

import folium
json = {
    "type": "FeatureCollection",
    "features": [
        {
            "bbox": [
                8.546326,
                47.417879,
                8.548813,
                47.420362
            ],
            "type": "Feature",
            "properties": {
                "summary": {
                    "distance": 343.2,
                    "duration": 50.5
                },
                "way_points": [
                    0,
                    15
                ]
            },
            "geometry": {
                "coordinates": [
                    [
                        8.548813,
                        47.420362
                    ],
                    [
                        8.548795,
                        47.420345
                    ],
                    [
                        8.548621,
                        47.420167
                    ]
                ],
                "type": "LineString"
            }
        }
    ]
}

m = folium.Map(location=[47.417879, 8.546326], zoom_start=13)

folium.features.GeoJson(json, style_function=lambda x: {'opacity': 1.0}).add_to(m)
m

Problem description

If a style_function is passed, folium tries to find an ID for the GeoJSON features. When no id field is present (not required in GeoJSONs AFAIK), it will try to pick a field from properties by checking if the values of the property fields are unique. However, the current implementation with set to check uniqueness fails when the property field values are dicts or lists.

Quick Fix

It works with a try/except around the the appropriate lines:

try:
    if len(set(feat['properties'][key] for feat in features)) == n:
        return 'feature.properties.{}'.format(key)
except TypeError:
    continue

I’d be happy with this if was my library, as far as I can see nothing else could raise a TypeError here. What do you think?

Output of 0.9.0

    530         for key in feature.get('properties', []):
    531             # try:
--> 532             if len(set(feat['properties'][key] for feat in features)) == n:
    533                 return 'feature.properties.{}'.format(key)
    534             # except TypeError:

TypeError: unhashable type: 'dict'

[nilsnolde]

True! Sorry, I pasted a small part of a full routing request and must’ve forgotten to paste the type, I edited the issue.

[Conengmo]

Thanks for your excellent bug report. This is indeed an issue. Your workaround seems fine, but I’ll look into it a bit, see if we can do something a bit more explicit.