Augusto Callejas wrote:

hi-

i'm writing a C++ class that i want to expose as a python class. one method in my class has an argument that takes in a python object that "implements" the iterator interface (that is the python object has defined "__iter__" and "__next__" and can be used in a "for x in y" loop).

how do i go about iterating over that python object in my C++ code?

for example:

void my_class::method(object my_iterable_obj) { // iterate over "my_iterable_obj" }

one method i tried was calling the "__next__" method explicity:

my_iterable_obj.attr("__next__")()

however, "__next__" raises a StopIteration exception when there are no more objects in the iterator. i could not find any examples in the boost python tutorials for handling python exceptions from c++.

is there another way i can go about this?

Boost 1.34 (the next version) will come with python::stl_input_iterator, which does exactly what you are trying to do. You can get the code now from Boost main CVS, or look at the implementation online. The interesting part is here: http://tinyurl.com/ybugtp. Thing to note: if you use PyIter_Next directly instead of obj.attr("__next__")(), you don't get an exception. -- Eric Niebler Boost Consulting www.boost-consulting.com