@Sky17: Cross Python is not for the faint of heart.
c.f., the insanity that is
my build script.
The TC part of it has been made slightly more user-friendly in an offshoot of this script,
koxtoolchain.
And as far as Python is concerned, a cross build of Python itself is already a "fun" experience, but a cross build of third-party Python modules with C/C++ code enters Lovecraftian territory...
See the numerous rants about it in the script, as there is no single, sane, official way to do this.
numpy is an even more special snowflake, because its build-system is it in itself a nightmare on top of a nightmare, so I just went with crossenv for that one...