swig -c++ -python foo_list.i
g++ -fPIC -c foo_list.cpp foo_list_wrap.cxx -I/usr/include/python3.4
g++ -shared foo_list.o foo_list_wrap.o -o _Foo.so
Using Foo in Python3:
>>> import Foo
>>> Foo.bar()
[2.0, 4.0]
>>> type(Foo.bar())
<class 'list'>
>>>