On Freitag 24 Oktober 2008, Robert Dailey wrote: > What happens if I do the following? > > using namespace boost::python; > > import( "__main__" ).attr( "new_global" ) = 40.0f; > import( "__main__" ).attr( "another_global" ) = 100.0f: > > > My main concern here is performance. I'm wondering if each call to > import() results in a disk query for the script in question and loads it > from there.
As Stefan said, bp::import is only a wrapper around the standard python
import, which (as you can easily check) does not load a module twice.
However, IIRC I read on some performance tuning page that an import-statement
within a frequently called function still does take some time. Again, this
can be easily checked (disclaimer: I did not set my cpufreq scheduler from
conservative to performance, so the numbers have to be considered bogus):
In [2]: %timeit import numpy
100000 loops, best of 3: 4.49 µs per loop
In [3]: %timeit None # for comparison
1000000 loops, best of 3: 216 ns per loop
In your above code, it should be trivial to assign the module to a variable
(of type bp::object) though.
--
Ciao, / / .o.
/--/ ..o
/ / ANS ooo
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