SymPy is a free and Python-based package that is lightweight and easy to use. It can be used beyond interactive tools and embedded in other applications. Surprisingly, SymPy has been integrated into various projects including Cadabra, ChemPy, and devito for different fields like tensor algebra and quantum field theory. Some other projects using SymPy include EinsteinPy for General Relativity, Lcapy for linear circuit analysis, and PyTorch TorchInductor for dynamic shapes and strides. Additionally, SymPy is used in Quantum Programming in Python, SageMath, and the Spyder environment for scientific development. The wide range of applications showcases the versatility and capabilities of SymPy.
https://www.sympy.org/en/index.html