Error creating buffers in shapefile

Question

I have a function to create buffers from everything in a shapefile, but I'm getting an error on some files: Record's geometry type does not match collection schema's geometry type: 'Polygon' != 'LineString'

Here's my function:

def buffer_file(src, dst, buffer):
  if not os.path.isfile(dst):
    with fiona.open(src) as input:
      input_meta = copy.deepcopy(input.meta)
      input_meta['schema']['properties'] = { 'id': 'int'}

      with fiona.open(dst, 'w', **input_meta) as output:
        for i, point in enumerate(input):
          output.write({
            'properties': { 'id': i },
            'geometry': mapping(shape(point['geometry']).buffer(buffer))
          })

What am I missing to make this work with all files? I works with most files I throw at it flawlessly. I just have some problem files.

Answer 1

Try to change destination geometry type into "Polygon". I guess geometry type of your input shapefile is LineString. But buffers are polygons. Briefly, you are trying to add polygons to shapefile whose geometry type is LineString.

def buffer_file(src, dst, buffer):
  if not os.path.isfile(dst):
    with fiona.open(src) as input:
      input_meta = copy.deepcopy(input.meta)
      input_meta['schema']['properties'] = { 'id': 'int'}

      # ADD THIS LINE
      input_meta["schema"]["geometry"] = "Polygon"

      with fiona.open(dst, 'w', **input_meta) as output:
        for i, point in enumerate(input):
          output.write({
            'properties': { 'id': i },
            'geometry': mapping(shape(point['geometry']).buffer(buffer))
          })