cartons 1.1.7

Simple OSRM routing and Folium map drawing toolkit

cartons

cartons is a lightweight Python toolkit for routing and interactive map visualization.

It combines the power of OSRM (Open Source Routing Machine) for route calculation with Folium for rendering beautiful interactive maps in HTML. With only a few lines of Python, you can calculate a route between two coordinates, extract route data such as geometry, distance, and duration, and display the result on a slippy map.

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Why cartons?

cartons is made for people who want to work with routes without building everything from scratch.

It gives you a clean and simple way to:

• calculate a route between two coordinates
• retrieve the full route object from OSRM
• draw the route on an interactive map
• save the map as an HTML file
• customize route color, line thickness, tiles, and attribution
• work with precomputed coordinate lists for fast visualization

It is intentionally lightweight, easy to understand, and easy to integrate into scripts, notebooks, demos, and small GIS projects.

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Preview

Geneva → Zürich

A long-distance route rendered across Switzerland.

Bern → Zürich

A shorter intercity route, useful for quick demos and examples.

Zoomed-in route detail

A close-up example showing that the route geometry stays clear and useful even at high zoom levels.

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Features

Routing

• Route calculation between two geographic coordinates
• Uses an OSRM routing server through routingpy
• Returns the full route object, not just a line
• Route object can expose useful data such as:
  • geometry
  • distance
  • duration

Visualization

• Draw routes on interactive Folium maps
• Save maps as .html
• Open generated maps in a browser
• Zoom and pan freely
• Use custom tile providers
• Use custom route color and line weight

Lightweight API

• Small, simple public API
• Minimal setup
• Easy to learn
• Good for scripts, prototypes, notebooks, and teaching

Fast drawing mode

• Draw an already existing coordinate list directly
• Useful when you already have route geometry and do not need to query OSRM again

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Installation

Install from PyPI:

pip install cartons

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Dependencies

cartons is built on top of:

• routingpy for OSRM access
• Folium for interactive maps

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Quick Start

import cartons
import webbrowser

# Bern → Zürich
m = cartons.draw(
    "https://router.project-osrm.org",
    7.4442153, 46.94686,
    8.5431302, 47.3668725,
    col="red",
    weight=5,
    tiles="CartoDB Positron",
    attribution="© CartoDB Positron",
    transport="car"
)

filename = "route.html"
m.save(filename)
webbrowser.open(filename)

This creates an interactive HTML map with the calculated route drawn on top.

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How cartons works

The workflow is simple:

Coordinates
    ↓
cartons.route()
    ↓
OSRM route calculation
    ↓
route object returned
    ↓
cartons.draw()
    ↓
Folium map
    ↓
Interactive HTML output

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Public API

The package exposes these functions:

• cartons.route(...)
• cartons.draw(...)
• cartons.simpledraw(...)

These are imported in the package root, so they are available directly after import cartons.

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API Reference

route()

Calculates a route using an OSRM server and returns the full route object.

cartons.route(base_url, lon1, lat1, lon2, lat2, transport="car")

Parameters

Parameter	Description
base_url	URL of the OSRM routing server
lon1	Longitude of the start point
lat1	Latitude of the start point
lon2	Longitude of the destination
lat2	Latitude of the destination
transport	Routing profile, such as car, bike, or foot

Returns

A route object returned by routingpy / OSRM.

What you can read from the returned route

Typical useful properties include:

• route.geometry
• route.distance
• route.duration

Example

import cartons

route = cartons.route(
    "https://router.project-osrm.org",
    7.4442153, 46.94686,
    8.5431302, 47.3668725,
    transport="car"
)

print("Distance (m):", route.distance)
print("Duration (s):", route.duration)
print("Number of geometry points:", len(route.geometry))

Friendly formatting example

print(f"Distance: {route.distance / 1000:.2f} km")
print(f"Duration: {route.duration / 60:.1f} min")

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draw()

Calculates a route and immediately draws it on a Folium map.

cartons.draw(
    base_url,
    lon1,
    lat1,
    lon2,
    lat2,
    col="blue",
    weight=5,
    tiles="CartoDB Positron",
    attribution="© CartoDB Positron",
    transport="car"
    marker=True
)

Parameters

Parameter	Description
base_url	URL of the OSRM routing server
lon1	Longitude of the start point
lat1	Latitude of the start point
lon2	Longitude of the destination
lat2	Latitude of the destination
col	Route line color
weight	Route line thickness
tiles	Tile source used by Folium
attribution	Attribution text for the tile provider
transport	Routing profile used by OSRM
marker	Boolean used if you want Markers at start/end coords.

Returns

A folium.Map object.

What it does internally

• calls route(...)
• reads route.geometry
• converts OSRM coordinate order into Folium coordinate order
• draws the route as a folium.PolyLine
• returns the map object

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simpledraw()

Draws a route directly from an existing list of coordinates. The pre-existing coordinates should be formatted like this:python [lat,lon],[lat,lon],[lat,lon]and so on.

cartons.simpledraw(
    coordslatlon,
    col="blue",
    weight=5,
    tiles="CartoDB Positron",
    attribution="© CartoDB Positron"
)

Parameters

Parameter	Description
coordslatlon	List of coordinates in [lat, lon] format
col	Route line color
weight	Route line thickness
tiles	Tile source used by Folium
attribution	Attribution text for the tile provider

Returns

A folium.Map object.

When to use simpledraw()

Use simpledraw() when:

• you already have route coordinates
• you want to visualize custom paths
• you do not want to call the routing server again
• you are drawing preprocessed or cached geometry

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Examples

simpleroute()

Calculates a route and immediately draws it on a Folium map but with less customisation and therefore less code.

cartons.draw(
    base_url,
    lon1,
    lat1,
    lon2,
    lat2,
    transport="car"
)

Parameters

Parameter	Description
base_url	URL of the OSRM routing server
lon1	Longitude of the start point
lat1	Latitude of the start point
lon2	Longitude of the destination
lat2	Latitude of the destination
transport	Routing profile used by OSRM

Returns

A folium.Map object.

What it does internally

• calls route(...)
• reads route.geometry
• converts OSRM coordinate order into Folium coordinate order
• draws the route as a folium.PolyLine
• returns the map object

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1. Calculate a route and inspect metadata

import cartons

route = cartons.route(
    "https://router.project-osrm.org",
    6.143158, 46.204391,   # Geneva
    8.541694, 47.376887,   # Zürich
    transport="car"
)

print(f"Distance: {route.distance / 1000:.2f} km")
print(f"Duration: {route.duration / 3600:.2f} h")

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2. Draw a route on an interactive map

import cartons

m = cartons.draw(
    "https://router.project-osrm.org",
    6.143158, 46.204391,   # Geneva
    8.541694, 47.376887,   # Zürich
    col="red",
    weight=6,
    transport="car"
)

m.save("geneva_zurich.html")

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3. Draw precomputed coordinates

import cartons

coords = [
    [46.94686, 7.4442153],
    [47.0, 7.7],
    [47.15, 8.0],
    [47.3668725, 8.5431302]
]

m = cartons.simpledraw(coords, col="red", weight=5)
m.save("custom_route.html")

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Use Cases

cartons is useful for:

• route visualization
• travel maps
• mobility demos
• logistics prototypes
• educational GIS examples
• interactive notebook demonstrations
• displaying routes in small web or data projects
• working with route geometry in Python

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Design Goals

This project is designed to be:

• simple
• readable
• practical
• lightweight
• easy to integrate
• easy to extend

Instead of being a huge GIS framework, cartons focuses on doing a small number of routing and visualization tasks well.

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Project Structure

cartons/
├── __init__.py
├── routing.py
├── simpleroute.py
└── display.py

routing.py

Handles route calculation through OSRM.

display.py

Handles map creation and route drawing through Folium.

simpleroute.py

Same as display.py but for simpleroute.

__init__.py

Exports the public API.

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Development

Clone the repository:

git clone https://github.com/AndPan3/cartons.git
cd cartons

Install in editable mode:

pip install -e .

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Notes

• cartons depends on access to an OSRM server
• the public demo server is great for testing, but production use may require your own server
• returned route data depends on the routing backend and profile used
• draw() is best when you want a full route calculation and visualization in one step
• simpledraw() is best when you already have coordinates
• simpleroute()is best for easy routing and map display.

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Roadmap Ideas

now availiable under otherfiles/next.txt

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Contributing

Contributions, suggestions, and improvements are welcome.

If you find a bug or want to improve the project:

1. Open an issue
2. Submit a pull request

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License

MIT License

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Author

AndPan3

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Acknowledgements

This project uses:

• OSRM for route computation
• routingpy as the Python routing interface
• Folium for map rendering
• CartoDB Positron / compatible tile providers for basemaps