# pyosmium

Provides Python bindings for the [Libosmium](https://github.com/osmcode/libosmium) C++
library, a library for working with OpenStreetMap data in a fast and flexible
manner.

[![Github Actions Build Status](https://github.com/osmcode/pyosmium/workflows/CI/badge.svg)](https://github.com/osmcode/pyosmium/actions?query=workflow%3ACI)

## Installation

Pyosmium works with Python >= 3.8. Pypy is known to not work. Support for
free-threading Python is currently in an experimental state.

Compiling and using pyosmium on 32bit architectures still works but is
not officially supported anymore. There are known issues around working
with large OSM IDs on 32bit systems.

### Using Pip

The recommended way to install pyosmium is via pip:

    pip install osmium

We provide binary wheels for Linux, MacOS and Windows 64bit architectures
for all actively maintained Python versions.

For other versions, a source wheel is provided. Make sure to install all
external dependencies first. On Debian/Ubuntu-like systems, the following
command installs all required packages:

    sudo apt-get install build-essential cmake libexpat1-dev zlib1g-dev libbz2-dev


### Installing from source

#### Prerequisites

pyosmium has the following dependencies:

 * [libosmium](https://github.com/osmcode/libosmium) >= 2.16.0
   (versions 2.21.0 to 2.23.0 have a known issue when processing extract diffs)
 * [protozero](https://github.com/mapbox/protozero)
 * [cmake](https://cmake.org/)
 * [Pybind11](https://github.com/pybind/pybind11) >= 2.7
 * [expat](https://libexpat.github.io/)
 * [libz](https://www.zlib.net/)
 * [libbz2](https://www.sourceware.org/bzip2/)
 * [Python Requests](https://docs.python-requests.org/)
 * [scikit-build-core](https://scikit-build-core.readthedocs.io)
 * a C++17-compatible compiler (Clang 13+, GCC 10+ are supported)


### Compiling from Source

Make sure to install the development packages for expat, libz and libbz2.

The appropriate versions for Libosmium and Protozero will be downloaded into
the `contrib` directory when building the source package:

    python3 -m build -s

Alternatively, provide custom locations for these libraries by setting
`Libosmium_ROOT` and `Protozero_ROOT`.

To compile and install the bindings, run

    pip install .

### Compiling for Development

To compile during development, you can use the experimental
[Editable install mode](https://scikit-build-core.readthedocs.io/en/latest/configuration/index.html#editable-installs)
of scikit-build-core:

Create a virtualenv with scikit-build-core and pybind11 preinstalled:

    virtualenv /tmp/dev-venv
    /tmp/dev-venv/bin/pip install scikit-build-core pybind11

Now compile pyosmium with:

    /tmp/dev-venv/bin/pip --no-build-isolation --config-settings=editable.rebuild=true -Cbuild-dir=/tmp/build -ve.


## Examples

The `example` directory contains small examples on how to use the library.
They are mostly ports of the examples in Libosmium and osmium-contrib.


## Testing

There is a small test suite in the test directory. This provides unit
test for the python bindings, it is not meant to be a test suite for Libosmium.

Testing requires `pytest` and `pytest-httpserver` and optionally
pytest-run-parallel and shapely. Install those into your dev environment:

    /tmp/dev-venv/bin/pip install --no-build-isolation --config-settings=editable.rebuild=true -Cbuild-dir=build -ve.[tests]

The test suite can be run with:

    /tmp/dev-venv/bin/pytest test

To test parallel execution on free-threaded Python, run:

    /tmp/dev-venv/bin/pytest test --parallel-threads 10 --iterations 100


## Documentation

To build the documentation you need [mkdocs](https://www.mkdocs.org/)
with the [mkdocstrings](https://mkdocstrings.github.io/)
and [jupyter](https://github.com/danielfrg/mkdocs-jupyter) extensions
and the [material theme](https://squidfunk.github.io/mkdocs-material/).

All necessary packages can be installed via pip:

    pip install osmium[docs]

To build the documentation run:

    mkdocs build

or to few it locally, you can use:

    mkdocs serve

Pregenerated man pages for the tools are available in `docs/man`. For rebuilding
the man pages run:

    cd docs
    make man

## Bugs and Questions

If you find bugs or have feature requests, please report those in the
[github issue tracker](https://github.com/osmcode/pyosmium/issues/).

For general questions about using pyosmium you can use the
[OSM development mailing list](https://lists.openstreetmap.org/listinfo/dev)
or ask on [OSM help](https://help.openstreetmap.org/).

## License

Pyosmium is available under the BSD 2-Clause License. See LICENSE.TXT.

## Authors

Sarah Hoffmann (lonvia@denofr.de) and otheres. See commit logs for a full
list.
