I am happy to announce Guppy 3 3.1.0 Guppy 3 is a library and programming environment for Python, currently providing in particular the Heapy subsystem, which supports object and heap memory sizing, profiling and debugging. It also includes a prototypical specification language, the Guppy Specification Language (GSL), which can be used to formally specify aspects of Python programs and generate tests and documentation from a common source. Guppy 3 is a fork of Guppy-PE, created by Sverker Nilsson for Python 2. This is a major feature release. The main news in this release: o Python 3.9 support, without subinterpreter support or inter-interpreter traversal. o Added .byprod classifier via tracemalloc, and .prod to print tracemalloc traceback. o Added .all to print all lines in a MorePrinter buffer. o Added R_INSET relation for being contained by an unordered set. License: MIT The project homepage is on GitHub: https://github.com/zhuyifei1999/guppy3 Enjoy, YiFei Zhu