Python doesn't add integration requirements. If you want to just use PyPy for something, then use it in good health (without fearing that your e-penis is tiny and will hamper your 'performance' because you didn't do whatever coldtea said is necessary for ULTIMATE SPEED).
Why the juvenile mockery about "e-penis" and "ULTIMATE SPEED" and such mocking? Are we 12 year old here?
I made my case explicitly, and it's about technical limitations of CPython that can (and, at some points WILL) be overcome. PyPy is a step in that direction, though not mature yet.
Python, in the form of the standard and most used implementation for scientific, technical etc programming, CPython, DOES add integration requirements.
It necessitates the use of C/Swig/Cython etc extensions for performance critical stuff. And it necessitates it, not because it puts a gun in your head or says so in some contract clause, but in the pragmatic way, that people find it's not fast enough for their needs in pure form.
That's why all the popular related Python projects are not written in pure Python, but in C/Fortran/et al (NumPy etc).
Integration is hell. This is a universal fact.
I'd rather pick a tool which doesn't add integration requirements!