This repository contains a Python script that converts MultiLineStrings to LineStrings. It was developed because I needed to manipulate public transport paths from OpenStreetMap data in a peculiar way, which required handling the data as LineStrings instead of MultiLineStrings.
This code should be used only when it is appropriate to convert a MultiLineString to a LineString, such as in my use case: it is reasonable to assume tha public transport paths in OpenStreetMap data can be meaningfully represented as simple LineStrings instead of MultiLineStrings. However, MultiLineStrings exist for a reason: they are used to represent geometries that cannot be accurately defined as a single LineString, such as when there are bifurcations, discontinuities, or complex branching structures. Make sure that your use case justifies the transformation and that the resulting LineStrings will still accurately represent the original geometries.
Be aware: it is not optimized code (yet)!
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├── MultiLine2Line.py # Main module containing the Multi2Line class
├── main.py # Main script to run the transformation
├── pyproject.toml # Poetry configuration file
├── .gitignore
└── README.md # This README file
The main functionality of this package is provided by the Multi2Line class in the MultiLine2Line.py script. You can use this class to transform MultiLineStrings into LineStrings according to a given threshold.
The main.py script in this repository is an example of how to use the Multi2Line class to process MultiLineStrings stored in a PostgreSQL database created with the Osmosis Pgsnapshot 0.6 schema. However, you can customize the script to fit your needs and use it with other data sources.
This project uses Poetry for dependency management. To install the required dependencies, run the following command in your terminal:
poetry install
Activate the Poetry virtual environment by running:
poetry shell
Then, execute the main.py script:
python main.py
The script will fetch MultiLineStrings from the PostgreSQL database, process them using the Multi2Line class, and update the database with the resulting LineStrings.
You can modify the main.py script to work with different data sources or adapt it to your specific needs. The key is to provide the Multi2Line class with MultiLineString objects and apply the transformation as needed.
For example, you can replace the PostgreSQL database interaction with another database system or even use files as your data source. Just make sure to update the script accordingly to fetch MultiLineStrings, process them using the Multi2Line class, and store the resulting LineStrings.