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Here's a script to buffer each feature, difference the original from
the buffered, and leave the difference in a new layer.<br>
The script operates on the active layer and assumes it is a polygon
layer. The results will be unpredictable if it's not.<br>
At the top of the script are two parameters, buf_dist and
buf_segments. These have the same meaning as the buffer operation in
geoprocessing. Remember that the buf_dist is in the units of the
CRS. My test data was in meters, so the buf_dist = 10000 is 10
kilometers. <br>
All the attributes are copied to the new layer, which is called
buffer_diff. Attributes that are based on the geometry are NOT
recalculated, so areas or perimeters will be wrong. <br>
If you run this from the python console, as each feature is
processed you'll get the message "Adding feature". After the last
feature is added there may be a noticeable pause before the canvas
is repainted. <br>
<br>
I've only tried this on a couple of layer files and they were both
in the same CRS, so let me know if this fails for your data and I'll
see what I can do. <br>
<br>
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