打印数组作为树

Question

我有一个数组（树），如：

['Humidity\n', ['High', ['Outlook\n', ['Sunny', ['Temp\n', ['Hot', ['Wind\n', ['Weak', ['No']], ['Strong', ['No']]]], ['Mild', ['No']]]], ['Overcast', ['Temp\n', ['Hot', ['Yes']], ['Mild', ['Yes']]]], ['Rain', ['Temp\n', ['Mild', ['Wind\n', ['Weak', ['Yes']], ['Strong', ['No']]]]]]]], ['Normal', ['Wind\n', ['Weak', ['Outlook\n', ['Rain', ['Yes']], ['Overcast', ['Temp\n', ['Cool', ['Yes']], ['Hot', ['Yes']]]], ['Sunny', ['Yes']]]], ['Strong', ['Temp\n', ['Cool', ['No']], ['Mild', ['Outlook\n', ['Rain', ['Yes']], ['Sunny', ['Yes']]]]]]]]] 

我想打印一棵树。这是我尝试

def printTree(treeToPrint, tab): 
    print tab + treeToPrint[0] 
    newTab = tab + "--" 
    nextTree = treeToPrint[1:] 
    for tree in nextTree: 
     print newTab + tree[0] 
     printTree(tree[1], newTab + "--") 

在打印输出一样：

Humidity 

--High 
----Outlook 

------Sunny 
--------Temp 

----------Hot 
------------Wind 

--------------Weak 
----------------No 
--------------Strong 
----------------No 
----------Mild 
------------No 
------Overcast 
--------Temp 

----------Hot 
------------Yes 
----------Mild 
------------Yes 
------Rain 
--------Temp 

----------Mild 
------------Wind 

--------------Weak 
----------------Yes 
--------------Strong 
----------------No 
--Normal 
----Wind 

------Weak 
--------Outlook 

----------Rain 
------------Yes 
----------Overcast 
------------Temp 

--------------Cool 
----------------Yes 
--------------Hot 
----------------Yes 
----------Sunny 
------------Yes 
------Strong 
--------Temp 

----------Cool 
------------No 
----------Mild 
------------Outlook 

--------------Rain 
----------------Yes 
--------------Sunny 
----------------Yes 

有人可以帮我代表了一个漂亮的格式，这棵树。

Answer 1

有时，pprint做得很好：

>>> from pprint import pprint 
>>> pprint(x) 
['Humidity\n', 
['High', 
    ['Outlook\n', 
    ['Sunny', 
    ['Temp\n', 
    ['Hot', ['Wind\n', ['Weak', ['No']], ['Strong', ['No']]]], 
    ['Mild', ['No']]]], 
... 

Answer 2

您可以使用此代码样本中发现here：

from turtle import * 
from types import * 

myTree = ["A",["B",["C",["D","E"],"F"],"G","H"]]; 

s = 50; 
startpos = (0,120) 
def cntstrs(list): 
    return len([item for item in list if type(item) is StringType]) 
def drawtree(tree, pos, head=0): 
    c = cntstrs(tree) 
    while len(tree): 
    goto(pos) 
    item = tree.pop(0) 
    if head: 
     write(item,1) 
     drawtree(tree.pop(0),pos) 
    else: 
     if type(item) is StringType: 
      newpos = (pos[0] + s*c/4 - s*cntstrs(tree), pos[1] - s) 
      down() 
      goto((newpos[0], newpos[1] + 15)) 
      up() 
      goto(newpos) 
      write(item,1) 
     elif type(item) is ListType: 
      drawtree(item,newpos) 

up() 
drawtree(myTree, startpos,1) 

该代码使用Python TkInter包在分离窗口中绘制树。 你可以通过这个命令安装在Linux Tkinter的：http://upload.wikimedia.org/wikipedia/commons/thumb/f/f7/Binary_tree.svg/220px-Binary_tree.svg.png

，你在你的意见建议：sudo apt-get install python-tk

，如果你想产生这样的事情你可以使用这个。但是，这不能被用于在控制台的打印..

Answer 3

这类似于：

from collections import deque 
class BTreeNode: 
    def __init__(self, data, left=None, right=None): 
     self.data = data 
     self.left = left 
     self.right = right 

    def insertNode(self, node): 
     if node.data < self.data: 
      if self.left == None: 
       self.left = node 
      else: 
       self.left.insertNode(node) 
     else: 
      if self.right == None: 
       self.right = node 
      else: 
       self.right.insertNode(node) 

    def printLevel(self): 
     """ Breadth-first traversal, print out the data by level """ 
     level = 0 
     lastPrintedLevel = 0 
     visit = deque([]) 
     visit.append((self, level)) 
     while len(visit) != 0: 
      item = visit.popleft() 
      if item[1] != lastPrintedLevel: #New line for a new level 
       lastPrintedLevel +=1 
       print 
      print item[0].data, 
      if item[0].left != None: 
       visit.append((item[0].left, item[1] + 1)) 
      if item[0].right != None: 
       visit.append((item[0].right, item[1] + 1)) 


bt=BTreeNode(1,left=BTreeNode(2,left=BTreeNode(4)), 
    right=BTreeNode(3,left=BTreeNode(5),right=BTreeNode(6)))  



bt.printLevel() 

输出：

1 
2 3 
4 5 6 

另一个替换：

import math 
from cStringIO import StringIO 

def show_tree(tree, total_width=33, fill=' '): 
    """Pretty-print a tree.""" 
    output = StringIO() 
    last_row = -1 
    for i, n in enumerate(tree): 
     if i: 
      row = int(math.floor(math.log(i+1, 2))) 
     else: 
      row = 0 
     if row != last_row: 
      output.write('\n') 
     columns = 2**row 
     col_width = int(math.floor((total_width * 1.0)/columns)) 
     output.write(str(n).center(col_width, fill)) 
     last_row = row 
    print output.getvalue() 
    print '-' * total_width 
    print 
    return 

show_tree(range(15)) 

打印：

   0     
     1    2   
    3  4  5  6  
7 8 9 10 11 12 13 14 
--------------------------------- 

现在，只需决定数据的根，并递归添加到BTree，然后您就在那里。