python simply not scaleable enough for google?

Terry Reedy tjreedy at udel.edu
Sun Nov 15 07:53:06 CET 2009


John Nagle wrote:
> Steven D'Aprano wrote:
>
>    Take a good look at Shed Skin.  One guy has been able to build a system
> that compiles Python to C++, without requiring the user to add 
> "annotations" about types.

In *only* compiles a subset of Python, as does Cython. Both cannot 
(currently) do generators, but that can be done and probably will 
eventually at least for Cython. Much as I love them, they can be 
rewritten by hand as iterator classes and even then are not needed for a 
lot of computational code.

I think both are good pieces of work so far.

 >  The system uses type inference to figure it out itself.
> You give up some flexibility; a variable can have only one primitive type
> in its life, or it can be a class object.  That's enough to simplify the
> type analysis to the point that most types can be nailed down before the
> program is run.  (Note, though, that the entire program may have to
> be analyzed as a whole.  Separate compilation may not work; you need
> to see the callers to figure out how to compile the callees.)
> 
>    It's 10 to 60x faster than CPython.
> 
>    It's the implementation, not the language.  Just because PyPy was a
> dud doesn't mean it's impossible. There are Javascript JIT systems
> far faster than Python.
> 
>    Nor do you really need a JIT system.  (Neither does Java; GCC has
> a hard-code Java compiler.  Java is JIT-oriented for historical reasons.
> Remember browser applets?)  If you're doing server-side work, the
> program's structure and form have usually been fully determined by
> the time the program begins execution.
> 
>                     John Nagle




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