Was working on a python related to avionics, came across a serious doubt whether code written in python would compile or run on a real time OS used in on board systems.
Language like Python, Java or C# require complex execution environment to run. This environment consists of tens and hundreds of thousands lines of code. It would be a huge work to review and certify it all, so certifying a Python application is not about reviewing ten lines of code that implement the needed algorithm.
While there are also various libraries for C or C++ as well, they are all optional. There is much more built-in stuff in high level languages, starting from the memory garbage collector that alone may be enough to make the implementation too complex to deal with.
Also, high level languages tend to have slightly unpredictable execution speed with short arbitrary pauses (they are not real time). This also limits where they could be used.