Pyhon 2.x or 3.x, which is faster?

[BartC]

On 06/03/2016 11:34, Tony van der Hoff wrote:
> Hi, I've been experimenting with a short test program under python 2.7
> and python 3.4.2. It's a simple read from file, and locate a word therein.
>
> I get the (subjective) impression that python2  is slightly faster than
> python3. Is that correct? Is there any documentation to support this?

I've also found that 3 was consistently slower than 2 on various 
benchmarks. Perhaps 10 to 20% slower (also 3.4 vs. 2.7).

One example (processing a jpeg file), both with CPython on Windows[1]:

Python 3.4:    6.8 seconds
Python 2.7:    5.4 seconds

But then:

PyPy:          2.1 seconds [2]

PyPy I think is only compatible with Python 3 code (there are a few 
other issues too).

([1] Windows Python I believe is a little slower than on Linux, for the 
same version of Python and on the same hardware. I think due to CPython 
being compiled with MSVC not gcc. But it would affect 2 and 3 equally.)

([2] With larger data, PyPy gets progressively faster compared with 
normal Python, as it can optimise big loops better. This test was with 
0.5 Mpixels of data)

-- 
Bartc