Nominatim as a library

Nominatim is an open-source geographic search engine (geocoder). It makes use of the data from OpenStreetMap to built up a database and API that allows to search for any place on earth and lookup addresses for any given geographic location. The conventional wisdom is that geocoding is such a computationally heavy task that it can only be done through a webservice. So far, Nominatim has been following this convention. While it is easy to install your own instance, it is still expected to be run as a service. However, if you care about privacy, then location data is not something you would want to regularly send to an external geocoding provider because it allows to create detailed movement profiles. We need the possibility to do geocoding directly on the device. The goal of this project is to transform Nominatim's code base so that it cannot be only be used as a web service but also as a local application or as a library inside another application. In the first phase, the PHP code of the search frontend will be ported to Python, which is much better suited for such a multi-use task. In the second phase, we explore if the rather heavy-weight PostgreSQL database can be transformed into an SQLite database to even further simplify using Nominatim as a library.