ContourPy: Contour Calculation for 2D Quadrilateral Grids

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.