Usually. Pypy is a counterexample, with a JIT compiler written in Python: https:...

jitl · on July 22, 2023

It’s written in a very restricted variant of Python, rpython: https://rpython.readthedocs.io/en/latest/rpython.html

mkl · on July 22, 2023

"RPython is a subset of Python2 that can be statically compiled. The PyPy interpreter is written mostly in RPython (with pieces in Python), while the RPython compiler is written in Python." - https://rpython.readthedocs.io/en/latest/getting-started.htm...