[Q] Overhead for lists as properties?

[Roeland Rengelink]

Oliver Hofmann wrote:
> 
> 'lo everyone!
> 
> Trying to figure out why appending to a list that is a class property
> takes so much longer than appending to a class attribute; this seems
> not to be the case for getting or setting other class attributes like
> integers.
> 
> [snip results]

First of all, to let properties work as expected, the Tester classes
should be new-style classes
(derived from object, for example). If I do that, I get:

         100043 function calls in 7.330 CPU seconds

   Ordered by: internal time
   List reduced from 12 to 10 due to restriction <10>

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        5    2.560    0.512    3.770    0.754
prof_prop.py:41(testSettingPropList)
        5    2.060    0.412    3.100    0.620
prof_prop.py:31(testSettingProp)
    50000    1.210    0.000    1.210    0.000 prof_prop.py:18(getB)
    50000    1.040    0.000    1.040    0.000 prof_prop.py:15(setA)
        5    0.270    0.054    0.270    0.054
prof_prop.py:36(testSettingNormList)
        5    0.150    0.030    0.150    0.030
prof_prop.py:26(testSettingNorm)
        1    0.040    0.040    7.330    7.330 prof_prop.py:46(main)
       10    0.000    0.000    0.000    0.000 prof_prop.py:9(__init__)
        0    0.000             0.000          profile:0(profiler)
       10    0.000    0.000    0.000    0.000 prof_prop.py:4(__init__)

Pretty much what you would expect. Half the overhead seems to be in
executing the additional Python code in getB and setA respectively. A
similar overhead is in finding and setting up the functions.

Hope this helps

Roeland

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