Method groupby

recipes/Python/498272_Rich_iterator_wrapper/recipe-498272.py:49–49

(self, keyfunc=None)

    def takewhile(self, predicate): return Iter(takewhile(predicate, self._it))
    def dropwhile(self, predicate): return Iter(dropwhile(predicate, self._it))
    def groupby(self, keyfunc=None): return Iter(groupby(self._it, keyfunc))
    def copy(self):
        self._it, new = tee(self._it)
        return Iter(new)