Python equivalence to inline functions or macros

Question

I just realized that doing

x.real*x.real+x.imag*x.imag

is three times faster than doing

abs(x)**2

where x

Answer 1

I'll agree with everyone else that such optimizations will just cause you pain on CPython, that if you care about performance you should consider PyPy (though our NumPy may be too incomplete to be useful). However I'll disagree and say you can care about such optimizations on PyPy, not this one specifically as has been said PyPy does that automatically, but if you know PyPy well you really can tune your code to make PyPy emit the assembly you want, not that you need to almost ever.