ContourPy: Contour Calculation for 2D Quadrilateral Grids

1.3.3 verified Tue May 12 auth: no python install: verified quickstart: stale

ContourPy is a Python library for calculating contours of 2D quadrilateral grids, written in C++11 and wrapped using pybind11. It offers algorithms used in Matplotlib, including the 2005 and 2014 versions, as well as a newer algorithm with additional features available in both serial and multithreaded versions. The current version is 1.3.3, released on March 7, 2026, with a release cadence of approximately every 2-3 months.

pip install contourpy

Common errors

error ModuleNotFoundError: No module named 'contourpy' ↓

cause The `contourpy` package is not installed in the current Python environment or is not accessible via `sys.path`.

fix

Ensure contourpy is installed using pip install contourpy or conda install -c conda-forge contourpy.

error ERROR: Could not build wheels for contourpy, which is required to install pyproject.toml-based projects. ↓

cause `pip` failed to compile the C++ extension of `contourpy` from source, often due to missing build tools (like a C++ compiler, `meson`, or `ninja`) or environment-specific issues.

fix

Install necessary build tools for your operating system (e.g., build-essential on Linux, Xcode on macOS, Visual C++ Build Tools on Windows) and then retry pip install contourpy. Alternatively, use conda install -c conda-forge contourpy to install pre-built binaries.

error ERROR: Could not find a version that satisfies the requirement contourpy==X.Y.Z (from versions: ...) ↓

cause The specified version of `contourpy` is not available for your current Python version or operating system, or there is a conflict with other installed packages requiring a different Python version.

fix

Check the Python version compatibility requirements for the desired contourpy version and upgrade your Python environment if needed. Try installing without a specific version constraint (pip install contourpy) to allow pip to find a compatible binary wheel, or manually select an older contourpy version known to be compatible with your Python.

error A module that was compiled using NumPy 1.x cannot be run in NumPy 2.0.0.dev0 as it may crash. ↓

cause The `contourpy` library, or a dependency of it, was compiled against a different major version of NumPy than the one currently installed, leading to potential Application Binary Interface (ABI) incompatibility.

fix

Downgrade NumPy to a version compatible with contourpy (typically <2.0 if contourpy hasn't released a 2.x compatible version) or upgrade contourpy to a version that officially supports NumPy 2.0. Reinstalling contourpy and its dependencies after adjusting NumPy versions is recommended.

Warnings

breaking Support for Python versions below 3.11 has been dropped in version 1.3.3. ↓

fix Upgrade to Python 3.11 or later.

deprecated The multithreaded option in the newer algorithm is considered experimental. ↓

fix Use with caution or opt for the serial version for stability.

breaking Missing required package: 'matplotlib'. The package 'matplotlib' was not found in the environment, preventing the script from running. ↓

fix Install the 'matplotlib' package using `pip install matplotlib` or ensure it is included in the project's dependency management.

breaking The 'matplotlib' package is not installed, leading to a ModuleNotFoundError. ↓

fix Install the matplotlib package using 'pip install matplotlib'.

Install compatibility verified last tested: 2026-05-12

python os / libc status wheel install import disk

3.10 alpine (musl) - - 0.20s 94.1M

3.10 slim (glibc) - - 0.17s 87M

3.11 alpine (musl) - - 0.32s 101.7M

3.11 slim (glibc) - - 0.28s 94M

3.12 alpine (musl) - - 0.30s 90.2M

3.12 slim (glibc) - - 0.28s 82M

3.13 alpine (musl) - - 0.24s 89.6M

3.13 slim (glibc) - - 0.28s 81M

3.9 alpine (musl) - - 0.21s 101.8M

3.9 slim (glibc) - - 0.17s 97M

Imports

contour_generator
```
from contourpy import contour_generator
```
Ensure correct import path to access contour generation functions

Quickstart stale last tested: 2026-04-23

A simple example demonstrating how to use ContourPy to generate and visualize contour lines and filled contours from a 2x2 grid of z values.

import numpy as np
from contourpy import contour_generator

# Create a 2x2 grid of z values
z = np.array([[0.0, 0.1], [0.2, 0.3]])

# Initialize the contour generator
cont_gen = contour_generator(z=z)

# Calculate contour lines at z-level 0.25
lines = cont_gen.lines(0.25)

# Calculate filled contours between z-levels 0.15 and 0.25
filled = cont_gen.filled(0.15, 0.25)

# Visualize the contours using Matplotlib
import matplotlib.pyplot as plt

fig, ax = plt.subplots()
for line in lines:
    ax.plot(line[:, 0], line[:, 1], color='red')
for polygon in filled[0]:
    ax.fill(polygon[:, 0], polygon[:, 1], color='gold', alpha=0.5)
plt.show()