The GIS layers for Seoul's pedestrian network are divided by a grid into many separate shapefiles. When merged into a single layer, the linestrings do not line up precisely at the endpoints, preventing us from using network analysis tools that rely on precisely connected links. This script resolves this by finding the link pairs that should be connected, and altering their geometry to share a vertex exactly. Beware: this will permanently alter your links shapefile.

This assumes you have already merged all the individual node layers into a single shapefile, and likewise have merged all the link layers into a single shapefile.

1. Make sure you have QGIS installed, with OSGEO4W shell.
2. Run OSGEO4W shell as administrator.
3. From shell, run py3-env to switch to the OSGEO python 3 environment.
4. Run pip install tqdm to make that module available in python-qgis.
5. From shell, navigate to this local repository folder.
6. Run the following command, replacing nodesLayer with the path to the merged nodes layer, and linksLayer with the path to the merged links layer: python-qgis merging_pedestrian_network_qgis_script.py nodesLayer linksLayer