Whilst there's less of an issue with Python 2.7, Python 3.4 relies on the pycrypto library for numerous wrappers/APIs/tools such as BlockTrail, pycoin, pybitcointools, etc etc.
The error I'm getting:
building 'Crypto.Random.OSRNG.winrandom' extension warning: GMP or MPIR library not found; Not building Crypto.PublicKey._fastmath. error: Unable to find vcvarsall.bat
It's an issue with the gcc C++ compiler for Windows, I understand, however the binaries offered in that solution, sadly, don't cover Python 3.4 (version for 3.3 won't cut it, unfortunately).
A solution - other than installing pseudo-Posix (ie Ming32) - would be very useful for those transitioning to Python 3.x
enter preformatted text here