Fast Google Polyline Encoding and Decoding

Installation

pip install pypolyline

Supported Python Versions

Python 3.9
Python 3.10
Python 3.11
Python 3.12
Python 3.13

Supported Platforms

Linux (manylinux*-compatible, x86_64 and aarch64)
macOS (x86_64 and arm64)
Windows 64-bit

Usage

Coordinates must be in (Longitude, Latitude) order

from pypolyline.cutil import encode_coordinates, decode_polyline

coords = [
            [52.64125, 23.70162],
            [52.64938, 23.70154],
            [52.64957, 23.68546],
            [52.64122, 23.68549],
            [52.64125, 23.70162]
         ]

# precision is 5 for Google Polyline, 6 for OSRM / Valhalla
polyline = encode_coordinates(coords, 5)
# polyline is 'ynh`IcftoCyq@Ne@ncBds@EEycB'
decoded_coords = decode_polyline(polyline, 5)

Error Handling

Failure to encode coordinates, or to decode a supplied Polyline, will raise a RuntimeError containing information about the invalid input.

How it Works

FFI and a Rust binary

Is It Fast

…Yes.
You can verify this by installing the polyline package, then running benchmarks.py, a calibrated benchmark using cProfile.
On an M2 MBP, The pure-Python test runs in ~2500 ms, the Flexpolyline benchmark runs in ~1500 ms and The Rust + Cython benchmark runs in around 80 ms (30 x and 17.5 x faster, respectively).

License

The Blue Oak Model Licence 1.0.0

Citing `Pypolyline`

If Pypolyline has been significant in your research, and you would like to acknowledge the project in your academic publication, we suggest citing it as follows (example in APA style, 7th edition):

Hügel, S. (2021). Pypolyline (Version X.Y.Z) [Computer software]. https://doi.org/10.5281/zenodo.5774925

In Bibtex format:

@software{Hugel_Pypolyline_2021,
author = {Hügel, Stephan},
doi = {10.5281/zenodo.5774925},
license = {MIT},
month = {12},
title = {{Pypolyline}},
url = {https://github.com/urschrei/simplification},
version = {X.Y.Z},
year = {2021}
}

urschrei/pypolyline