Descartes

1.1.0 · deprecated · verified Sun Apr 12

Descartes is a Python library that enables the use of geometric objects, typically from the Shapely library, as Matplotlib paths and patches. It provides a convenient way to integrate vector geometries into Matplotlib plots. The current version is 1.1.0, released on January 17, 2017. Due to its last release date, the project has a very slow or effectively ceased release cadence, leading to compatibility challenges with newer dependencies.

Warnings

breaking Descartes 1.1.0 is incompatible with Shapely versions 2.0 and newer. Using `PolygonPatch` (or other patches) with `Shapely >= 2.0` will result in an `IndexError: too many indices for array` due to changes in how Shapely exposes exterior/interior coordinates.
Fix: Downgrade Shapely to a version less than 2.0 (e.g., `pip install 'Shapely<2.0'`) or consider migrating to a different plotting solution that natively supports newer Shapely versions, such as `matplotlib.patches.Polygon` directly, or libraries like GeoPandas (which has dropped descartes as a dependency).
deprecated The Descartes library is no longer actively maintained; its last release was in January 2017. This means it will not receive updates for new features, bug fixes, or official compatibility with newer versions of Python or its dependencies (like Matplotlib or Shapely). Other libraries that previously relied on Descartes are migrating away from it.
Fix: Be aware of potential compatibility issues. For new projects, consider using native Matplotlib patching capabilities with Shapely geometries or explore other maintained geospatial plotting libraries.
gotcha While Descartes handles basic geometric objects, for more complex GIS plotting needs (e.g., coordinate system transformations, basemaps), you will likely need to integrate it with other libraries like Matplotlib's Basemap or GeoPandas (though GeoPandas is moving away from Descartes).
Fix: Plan for additional libraries for advanced geospatial plotting. Understand that Descartes primarily acts as a bridge between Shapely geometries and Matplotlib patches.

Install

pip install descartes Install Descartes

Imports

PolygonPatch
```
from descartes import PolygonPatch
```
PointPatch
```
from descartes import PointPatch
```
While `descartes.patch` might work, the direct `descartes` import is the common and intended pattern.
LineStringPatch
```
from descartes import LineStringPatch
```

Quickstart

This quickstart demonstrates how to create a `shapely.geometry.Polygon` and then render it on a Matplotlib axis using `descartes.PolygonPatch`. The `PolygonPatch` converts the geometric object into a displayable Matplotlib patch.

import matplotlib.pyplot as plt
from shapely.geometry import Polygon
from descartes import PolygonPatch

# Define a simple polygon using Shapely
polygon = Polygon([(0, 0), (1, 1), (0, 1), (0, 0)])

# Create a Matplotlib figure and axes
fig, ax = plt.subplots()

# Create a PolygonPatch from the Shapely Polygon
# You can customize color (fc), edge color (ec), alpha, etc.
patch = PolygonPatch(polygon, fc='blue', ec='black', alpha=0.5, zorder=2)

# Add the patch to the axes
ax.add_patch(patch)

# Set axes limits to display the polygon
minx, miny, maxx, maxy = polygon.bounds
ax.set_xlim(minx - 0.1, maxx + 0.1)
ax.set_ylim(miny - 0.1, maxy + 0.1)
ax.set_aspect('equal', adjustable='box') # Keep aspect ratio

plt.title("Shapely Polygon plotted with Descartes")
plt.show()

view raw JSON →