fix __geo_interface__ if parts or points is empty list #101
Conversation
|
|
||
| """ Case parts or points is empty """ | ||
| if not self.parts or not self.points: | ||
| return False |
There was a problem hiding this comment.
False? I am not sure about this. how does geojson handle empty geometries?
There was a problem hiding this comment.
False is a valid value for geojson data structure. (https://geojson.org/geojson-spec.html#geometry-objects) I did some tests with geojson that contains a false value in geometry fields in GIS tools, and i not found erros.
There was a problem hiding this comment.
There doesn't seem to be an empty geometry type defined in GeoJSON, but it does state that feature objects without a geometry can be specified with JSON null value, which would be None rather than False in Python.
From the previous link:
A feature object must have a member with the name "geometry". The value of the geometry member is a geometry object as defined above or a JSON null value.
I also think None makes more sense since there literally is "none" geometry object.
|
Thanks for this @Tisp. However, I believe the unbound local error happens for good reasons. Having geo_interface return False or None would imply that this is a null-geometry. But geo_interface is already built to return None when the shape type is set to NULL. This means your code was processing a real geometry, specifically a polyline or polygon geometry which should always contain a So while the error message is being raised correctly it is not very informative. Perhaps instead of returning False we can return a more informative exception if the parts attribute is empty? Furthermore, this should only be checked for polyline or polygon types, as these are the only ones expected to have the |
|
I agree. Right now I'm handling the |
|
Fixed this now, raises a generic Exception when this happens (but see #146). Also raises error if shape type is beyond what the GeoJSON specification can represent. |
Fixes UnboundLocalError when shapes have empty parts or points
File "/usr/local/lib/python2.7/site-packages/shapefile.py", line 174, in __geo_interface__ coordinates.append(tuple([tuple(p) for p in self.points[part:]])) UnboundLocalError: local variable 'part' referenced before assignment