how to loop inside NLTK Arabic Parser grammar

[Boshra Nour]

I am trying to develop Arabic parser by using the NLTK tool in Python
I am using the groucho grammar but whenever I try to loop or to access this grammar an error message appears saying that it is not iterable,so is there is any way to access it or to loop inside it ?

[bvdet]

What is "groucho grammer"? Can you post your code that causes the error and the full error traceback?