many small tasks: swig
13.140625
many small tasks: boost python
13.65625
many small tasks: pybind11
26.71875
many small tasks: native python
13.359375
one big task: swig
0.734375
one big task: boost python
0.71875
one big task: pybind11
0.71875
one big task: native python
17.84375

generated file size comparison:
pybind11: 92kb
boost python: 108kb
swig: 30kb