python之将数组打印为树

我有一个像这样的数组(树):

['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']]]]]]]]] 

我想把它打印成一棵树。这是我的尝试

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 + "--") 

打印输出如下:

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 

谁能帮我用漂亮的格式表示这棵树。