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