I have a set of polygons representing administrative districts. The districts were digitized by hand, and there are small spaces between polygons where the polygons should be touching. There are probably also overlapping polygons. How can I have the polygons snap together, filling the gaps and removing overlap?
QGIS / ArcGIS or Python library solution preferred (but algorithm suggestions welcome)
Old school ArcInfo had a "clean" function - I think they did the same thing in geoprocessing if you use a geodb. In that function you set a tolerance for snapping lines and points together. The clean gets rid of all those slivers (the technical term for what you are talking about).
For Qgis:
This thread should be of some help to you http://hub.qgis.org/issues/3126
I know this post is 6 months old but ayway, you can use the Integrate tool in ArcGIS which should do what you want.
You can find a tool in the ArcGIS world called: geometry repair. You can use the python API.
来源：https://stackoverflow.com/questions/6345343/snapping-polygons-together