how fast is Python?

Andrew Dalke adalke at
Thu Aug 21 00:00:19 CEST 2003

> However, there are definitely cases where a lot of code would need to
> be optimized, and so I ask the question:  How fast is Python, compared
> to say a typical optimizing C/C++ compiler?

Highly dependent on context.  I use factor of 10-20 as a ballpark,
with factor of 100 for some things like low-level string processing.
Eg, I've got a pure Python regexp engine which clocks at about x80
slower than sre.

> what could be done to optimize the interpreter?  Are any parts written
> in assembly?  Could things like hash tables be optimized with parallel
> units such as MMX?  Etc.

Spend a few tens of millions on developing just-in-time compilers
and program analysis.  That worked for Java.

Nothing is written in assembly, except that C can be considered
a portable assembly language.  Otherwise ports to different platforms
would be a lot more difficult.

I would hope that the C compiler could optimize the C code
sufficiently well for the hardware, rather than tweaking the
code by hand.  (Though I know of at least one person who sent
in a patch to gcc to optimize poorly written in-house code.
 Rather circuitous way to fix things, but it worked.)

                    dalke at

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