Brython-3.9.2

The main new feature is a rewriting of the re module. The previous version used a pure-Python version of the CPython module _sre; it took a long time to import and was slow on execution. The new module (libs/python_re.js) loads immediately and its execution is much faster (at least 30 times), although still much slower than the CPython module.

The version also introduces a change in the implementation of strings with code points adressable with more than 2 bytes ("surrogate pairs").