我的树是这样的（第一个数字是级别，第二个数字是该级别的索引）：
11
12
13
21
22
31
32
33
当我遍历树时，我得到了这个：
----11
----12
------21
--------31
--------32
--------33
------22
----13
以下是代码：
from xml.etree import ElementTree
def perf_func(elem, func, level=0):
func(elem,level)
for child in elem.getchildren():
perf_func(child, func, level+1)
def print_level(elem,level):
print '-'*level+elem.tag
with open('Map.xml', 'rt') as f:
tree = ElementTree.parse(f)
perf_func(Tree, print_level)
更新：这是我正在使用的读取数据。我试图只打印文本（PlainText不为null）和此文本的格式
<ap:OneTopic>
<ap:Topic Dirty="0000000000000001" OId="PktS/h+L5EeSqM/4hMH9JA==" Gen="0000000000000000">
<ap:SubTopics>
<ap:Topic Dirty="0000000000000001" OId="Tyvwk/tRCUGYSZe8Gm1hKw==" Gen="0000000000000000">
<ap:SubTopics>
<ap:Topic Dirty="0000000000000001" OId="g1+iDTazMUaJf6HWSIz69Q==" Gen="0000000000000000">
<ap:SubTopics>
<ap:Topic Dirty="0000000000000001" OId="KTsoZbCe/Uq0IgYi9JVRvQ==" Gen="0000000000000000">
<ap:TopicViewGroup ViewIndex="0"/>
<ap:Text Dirty="0000000000000001" PlainText="1123" ReadOnly="false">
<ap:Font/>
</ap:Text>
</ap:Topic>
</ap:SubTopics>
<ap:TopicViewGroup ViewIndex="0">
<ap:Collapsed Collapsed="false" Dirty="0000000000000001"/>
</ap:TopicViewGroup>
<ap:Text Dirty="0000000000000001" PlainText="1121" ReadOnly="false">
<ap:Font/>
</ap:Text>
</ap:Topic>
<ap:Topic Dirty="0000000000000001" OId="QzZ2AAYYS0a5aE+v2z9dkA==" Gen="0000000000000000">
<ap:TopicViewGroup ViewIndex="0"/>
<ap:Text Dirty="0000000000000001" PlainText="1122" ReadOnly="false">
<ap:Font/>
</ap:Text>
</ap:Topic>
</ap:SubTopics>
<ap:TopicViewGroup ViewIndex="0">
<ap:Collapsed Collapsed="false" Dirty="0000000000000001"/>
</ap:TopicViewGroup>
<ap:Text Dirty="0000000000000001" PlainText="11" ReadOnly="false">
<ap:Font/>
</ap:Text>
</ap:Topic>
<ap:Topic Dirty="0000000000000001" OId="7qQAOqWlmkKn4t4Z2DMd5A==" Gen="0000000000000000">
<ap:SubTopics>
<ap:Topic Dirty="0000000000000001" OId="ro5nEHjge0qcWHXXO7/8sA==" Gen="0000000000000000">
<ap:TopicViewGroup ViewIndex="0"/>
<ap:Text Dirty="0000000000000001" PlainText="1221" ReadOnly="false">
<ap:Font/>
</ap:Text>
</ap:Topic>
<ap:Topic Dirty="0000000000000001" OId="R5CK83KQTEquBBqivm8Lmg==" Gen="0000000000000000">
<ap:SubTopics>
<ap:Topic Dirty="0000000000000001" OId="xGn0UoleIU681h90xtm7oQ==" Gen="0000000000000000">
<ap:TopicViewGroup ViewIndex="0"/>
<ap:Text Dirty="0000000000000001" PlainText="12223" ReadOnly="false">
<ap:Font/>
</ap:Text>
</ap:Topic>
</ap:SubTopics>
<ap:TopicViewGroup ViewIndex="0">
<ap:Collapsed Collapsed="false" Dirty="0000000000000001"/>
</ap:TopicViewGroup>
<ap:Text Dirty="0000000000000001" PlainText="1222" ReadOnly="false">
<ap:Font/>
</ap:Text>
</ap:Topic>
</ap:SubTopics>
<ap:TopicViewGroup ViewIndex="0">
<ap:Collapsed Collapsed="false" Dirty="0000000000000001"/>
</ap:TopicViewGroup>
<ap:Text Dirty="0000000000000001" PlainText="12" ReadOnly="false">
<ap:Font/>
</ap:Text>
</ap:Topic>
<ap:Topic Dirty="0000000000000001" OId="jH0FY5i1/Uu7cPCFcFgoCQ==" Gen="0000000000000000">
<ap:SubTopics>
<ap:Topic Dirty="0000000000000001" OId="TX7JXfIvn0WOpoqvUCKzUA==" Gen="0000000000000000">
<ap:TopicViewGroup ViewIndex="0"/>
<ap:Text Dirty="0000000000000001" PlainText="21" ReadOnly="false">
<ap:Font/>
</ap:Text>
</ap:Topic>
<ap:Topic Dirty="0000000000000001" OId="mOwoPsJM20SjK2j7RwqNow==" Gen="0000000000000000">
<ap:SubTopics>
<ap:Topic Dirty="0000000000000001" OId="/BWUGWt6mE6vUXJZDRxskw==" Gen="0000000000000000">
<ap:TopicViewGroup ViewIndex="0"/>
<ap:Text Dirty="0000000000000001" PlainText="31" ReadOnly="false">
<ap:Font/>
</ap:Text>
</ap:Topic>
<ap:Topic Dirty="0000000000000001" OId="sqYG4DtARUq2NplBb7atEg==" Gen="0000000000000000">
<ap:TopicViewGroup ViewIndex="0"/>
<ap:Text Dirty="0000000000000001" PlainText="32" ReadOnly="false">
<ap:Font/>
</ap:Text>
</ap:Topic>
<ap:Topic Dirty="0000000000000001" OId="QfxZRuomGk6kllnrvrT25w==" Gen="0000000000000000">
<ap:TopicViewGroup ViewIndex="0"/>
<ap:Text Dirty="0000000000000001" PlainText="33" ReadOnly="false">
<ap:Font/>
</ap:Text>
</ap:Topic>
</ap:SubTopics>
<ap:TopicViewGroup ViewIndex="0">
<ap:Collapsed Collapsed="false" Dirty="0000000000000001"/>
</ap:TopicViewGroup>
<ap:Text Dirty="0000000000000001" PlainText="22" ReadOnly="false">
<ap:Font/>
</ap:Text>
</ap:Topic>
</ap:SubTopics>
<ap:OneBoundary>
<ap:Boundary Dirty="0000000000000001" OId="paP2GTbrYEuUuE6rusovoA==" Gen="0000000000000000">
<ap:BoundaryViewGroup ViewIndex="0"/>
<ap:BoundaryShape BoundaryShape="urn:mindjet:SummaryArc" Dirty="0000000000000001"/>
<ap:OneSummaryTopic>
<ap:Topic Dirty="0000000000000001" OId="QjLln9LrlUSlfS87gzyGxA==" Gen="0000000000000000">
<ap:TopicViewGroup ViewIndex="0"/>
<ap:Text Dirty="0000000000000001" PlainText="Call out topic" ReadOnly="false">
<ap:Font/>
</ap:Text>
</ap:Topic>
</ap:OneSummaryTopic>
</ap:Boundary>
</ap:OneBoundary>
<ap:TopicViewGroup ViewIndex="0">
<ap:Collapsed Collapsed="false" Dirty="0000000000000001"/>
</ap:TopicViewGroup>
<ap:Text Dirty="0000000000000001" PlainText="13" ReadOnly="false">
<ap:Font Color="ffff0000"/>
</ap:Text>
</ap:Topic>
</ap:SubTopics>
<ap:TopicViewGroup ViewIndex="0">
<ap:Collapsed Collapsed="false" Dirty="0000000000000001"/>
</ap:TopicViewGroup>
<ap:SubTopicsShape SubTopicsVerticalAlignment="urn:mindjet:Middle" Dirty="0000000000000000"/>
</ap:Topic>
</ap:OneTopic>
使用上面引用的代码，我得到了这个（有些＆＃34;如果＆＃34;条件已从引用的代码中删除）
--------1123
------1121
------1122
----11
------1221
--------12223
------1222
----12
------21
--------31
--------32
--------33
------22
--------Call out topic
----13
-----ffff0000