The F-35 is about embedded software, i.e. it's about C/C++ vs. Ada, not C/C++ vs. Python. The reason they didn't go with Ada was a lack of programmers, not language design issues, as I recall.

In any event, I don't think the F-35 with its numerous software-related problems [1, 2] is a good advertisement for C++.

[1] http://spectrum.ieee.org/riskfactor/aerospace/military/f35-s...

[2] http://www.nextgov.com/defense/2013/03/f-35-joint-strike-fig...