Python实现树的先序、中序、后序排序算法示例

#encoding=utf-8
class Tree():
  def __init__(self,leftjd=0,rightjd=0,data=0):
    self.leftjd = leftjd
  　　self.rightjd = rightjd
  　　self.data = data 
class Btree():
  def __init__(self,base=0):
  　　self.base = base
  #前序遍历 根左右
  def qout(self,jd):
    if jd == 0:
    return
  print jd.data
  self.qout(jd.leftjd)
  self.qout(jd.rightjd)
  #中序遍历 左根右
  def mout(self,jd):
  if jd == 0:
    return
  self.mout(jd.leftjd)
  print jd.data
  self.mout(jd.rightjd)
  #后序遍历 左右根
  def hout(self,jd):
  if jd == 0:
    return
  self.hout(jd.leftjd)
  self.hout(jd.rightjd)
  print jd.data
jd1 = Tree(data=8)
jd2 = Tree(data=9)
base = Tree(jd1,jd2,7)
x = Btree(base)
x.qout(x.base)
print '\r\n'
x.mout(x.base)
print '\r\n'
x.hout(x.base)