> Yes, It's mainly because a grouper written on Python. When it will be
> implemented in C, the difference will be less. This function will be
> useful beside struct.

I'm not against adding useful C tools to itertools, but you may have to
convince Raymond ;)

> As for extending Struct, what you think about a more powerful feature?
> About a method which returns not an iterator, but an iterable and
> indexable sequence. Here is a sample Python implementation.

I'll take a look, but the question is how complex a C implementation
would be.