Python Question

Consider this generator function: def mystery_generator (a, seq): for x in seq: yield x else: a-= 1 What is it doing? 0 it drops the first a>=0 values from sequence seq. 0 it outputs just the first a>=0 values from sequence seq. O it outputs the first x values greater or equal to a O it drops the first a-1 values from sequence seq O it outputs the first x values less than a