class node():
    def __init__(self):
        self.split_atrr = None
        self.split_thres = None
        self.left_child = None
        self.right_child = None
    def get_name(self):
        return 'Node'
class leaf():
    def __init__(self):
        self.label = None
    def get_nmae(self):
        return 'leaf'

class decision_tree():
    def __init__(self):
        self.root = None
    def fit(self, x, y):
        self.spliter(x,y,self.root)
        return 0
    def spliter(self,x,y,tree)
        tree = node()  #this does not make self.root as a node
        spliter(x,y,tree.left_child) #this line does not work unless I change the __init__ to "self.root = node()"
# Wish  to recursively expand the tree.
#However, return error saying tree.left_child is none type