I am trying to carry out a simple zonal statistics task in python, and am having trouble getting this to work.
I have a raster layer (in black/grayscale) and a roads polygons layer (in green, actually polygons since I drew buffers around a lines layer), shown below:
The roads layer has many different road "segments", each of which is a separate polygon/feature/row in the shapefile attribute table. What I am trying to do is, for each road segment, find the average pixel value of the underlying raster layer, within that specific road segment polygon, and finally append that new column of average values to the road layer's attribute table. This task works fine in QGIS, using the "Zonal statistics". However, I cannot seem to get this same process to work in python.
I am using the following zonal_stats function from the rasterstats module to try and perform my zonal statistics task with the following, referring to this zonal_stats documentation: https://pythonhosted.org/rasterstats/
This looks like such a simple function to use, with simple, straightforward arguments, and so I am simply running:
zonal_stats("roads.shp", "raster.tif", stats="count min mean max median")
And I get the following error traceback:
--------------------------------------------------------------------------- AttributeError Traceback (most recent call last) ~\AppData\Local\Temp/ipykernel_17488/2186187301.py in <module> 5 roads_buffers = gpd.read_file('roads_buffers.shp') 6 ----> 7 zonal_stats("roads_buffers.shp", "Fresno_Rasters/Fresno_NOx_PopWeighted.tif", stats="count min mean max median") ~\AppData\Roaming\Python\Python39\site-packages\rasterstats\main.py in zonal_stats(*args, **kwargs) 29 The only difference is that ``zonal_stats`` will 30 return a list rather than a generator.""" ---> 31 return list(gen_zonal_stats(*args, **kwargs)) 32 33 ~\AppData\Roaming\Python\Python39\site-packages\rasterstats\main.py in gen_zonal_stats(vectors, raster, layer, band, nodata, affine, stats, all_touched, categorical, category_map, add_stats, zone_func, raster_out, prefix, geojson_out, boundless, **kwargs) 151 features_iter = read_features(vectors, layer) 152 for _, feat in enumerate(features_iter): --> 153 geom = shape(feat['geometry']) 154 155 if 'Point' in geom.type: ~\AppData\Roaming\Python\Python39\site-packages\shapely\geometry\geo.py in shape(context) 100 else: 101 ob = context --> 102 geom_type = ob.get("type").lower() 103 if 'coordinates' in ob and _is_coordinates_empty(ob['coordinates']): 104 return _empty_shape_for_no_coordinates(geom_type) AttributeError: 'NoneType' object has no attribute 'get'
I have tried searching online, and diagnosing this, but I cannot figure out what
AttributeError: 'NoneType' object has no attribute 'get' is telling me, because I do not know what
'get' means or where this function is coming from. How can I fix this issue so that I can get my zonal statistics operation running?