Iterates over the elements of list grouping elements by the specified amount.

group_iterate.py

def group_iterate(list = [], group_by = 1):
    """
    Iterates over the elements of list grouping elements by the specified amount.
    
    Example usage:
    >>> for a in group_iterate(range(12), 3):
    ...   print a
    ... 
    (0, 1, 2)
    (3, 4, 5)
    (6, 7, 8)
    (9, 10, 11)
    """
    for i in zip(*[list[i::group_by] for i in xrange(group_by)]):
        yield i