IT IS PYTHON LANGUAGE

def num_positives (self) - int: ""Return the number of positive integers in this tree Precondition: all items in this tree are integers Remember, 0 is *not* positive. >>>t1-Tree (17, []) t1.num_ positives() >>>t2Tree (-10, ]) >>t2.num_positives() >t3 Tree (1, [Tree (-2, [), Tree (10, []), Tree (-30, [)1) >t3.num_positives() 2 # if self.is-empty(): # elif self-subtrees-D- # else: # for subtree in self._subtrees: ...subtree.num_positives(). pass