By corbet As all Python developers discover sooner or later, Python is a rapidly
evolving language whose community occasionally makes changes that can break
existing programs. The switch to Python 3 is the most prominent
example, but minor releases can include significant changes as well. The
CPython interpreter can emit warnings for upcoming incompatible changes,
giving developers time to prepare their code, but those warnings are
suppressed and invisible by default. Work is afoot to make them visible,
but doing so is not as straightforward as it might seem.