Python vs. Lisp -- please explain

[Paul Rubin]

Steven D'Aprano <steve at REMOVETHIScyber.com.au> writes:
> > > efficient? Is there some *specific* basic reason it's tough?  Or is it
> > > that this type of problem in general is tough, and Lisp has 40+ years
> > > vs Python's ~15 years?
> >
> > It is by design. 
> Python is not slow by design. Python is dynamically typed by design, and
> relative slowness is the trade-off that has to be made to give dynamic
> types.

I think both of you are missing the point of the question, which is
that Lisp is dynamically typed exactly the way Python is and maps to
Python almost directly; yet good Lisp implementations are much faster
than CPython.  

> The Python developers have also done marvels at speeding up Python since
> the early days, with the ultimate aim of the PyPy project to make Python
> as fast as C, if not faster. In the meantime, the question people should
> be asking isn't "Is Python fast?" but "Is Python fast enough?".

That is the real answer: CPython doesn't reach performance parity with
good Lisp implementations, but is still fast enough for lots of
purposes.  Psyco and PyPy are ongoing efforts to close the performance
gap and which are showing promise of success.