[Discuss-gnuradio] Should return the number of input or the number of output?

[Activecat]

Dear Sir,

A python sink block created by gr_modtool has below work() function, it returns the number of input items.

    def work(self, input_items, output_items):
        in0 = input_items[0]
        # <+signal processing here+>
        return len(input_items[0])

But a c++ sink block created by gr_modtool has the work() function return the number of output items (noutput_items).

It sounds contradict. Is there any error happening?

Regards,
Activecat