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python模块之xml.etree.ElementTree
Python有三种方法解析XML,SAX,DOM,以及ElementTree
###1.SAX (simple API for XML )
pyhton 标准库包含SAX解析器,SAX是一种典型的极为快速的工具,在解析XML时,不会占用大量内存。
但是这是基于回调机制的,因此在某些数据中,它会调用某些方法进行传递。这意味着必须为数据指定句柄,
以维持自己的状态,这是非常困难的。
###2.DOM(Document Object Model)
与SAX比较,DOM典型的缺点是比较慢,消耗更多的内存,因为DOM会将整个XML数读入内存中,并为树
中的第一个节点建立一个对象。使用DOM的好处是你不需要对状态进行追踪,因为每一个节点都知道谁是它的
父节点,谁是子节点。但是DOM用起来有些麻烦。
###3.ElementTree(元素树)
ElementTree就像一个轻量级的DOM,具有方便友好的API。代码可用性好,速度快,消耗内存少,这里主要
介绍ElementTree。
一 基本知识
1、插入节点
Element.insert(index, element) 、Element(tag[, attrib][, **extra]) 、SubElement(parent, tag[, attrib[, **extra]]) 、Element.append(subelement)
2、删除节点
Element.remove(subelement) 删除一个节点、Element.clear()删除该节点下所有子节点
3、在节点中插入属性
Element.set(key, value)
4、查找节点
a) Element.getiterator b) Element.getchildren c) Element.find d) Element.findall
#!/usr/bin/python # -*- encoding: utf-8 -*- import os import sys import os.path import xml.etree.ElementTree as ET def read_xml(xmlFile, destDir): # print ‘==----------------=‘,ET.parse(xmlFile) # 加载XML文件(2种方法,一是加载指定字符串,二是加载指定文件)c:\xml\1.xml ‘‘‘ <?xml version="1.0" ?> <root> <FILE_DIRECTORY NAME="ca002"> <FILE_DIRECTORY NAME="RT_CA"> <FILE_NAME NAME="0000.obj"> <COFF_FILE_HEAD BEGIN="0" END="20"> <Machine>X86</Machine> <NumberOfSections>2</NumberOfSections> <PointerToSymbolTable>21205</PointerToSymbolTable> <NumberOfSymbols>107</NumberOfSymbols> <SizeOfOptionalHeader>0</SizeOfOptionalHeader> <Characteristics>0</Characteristics> </COFF_FILE_HEAD> <COFF_IMAGE_SECTIONS> <COFF_IMAGE_SECTION INDEX="0"> <Name>.rdata</Name> <SizeOfRawData>5064</SizeOfRawData> <PointerToRawData>100</PointerToRawData> <PointerToRelocations>0</PointerToRelocations> <PointerToLinenumbers>0</PointerToLinenumbers> <NumberOfRelocations>0</NumberOfRelocations> <NumberOfLinenumbers>0</NumberOfLinenumbers> </COFF_IMAGE_SECTION> </COFF_IMAGE_SECTIONS> </FILE_NAME> </FILE_DIRECTORY> </FILE_DIRECTORY> </root> :param xmlFile: :param destDir: :return: ‘‘‘ tree = ET.parse(xmlFile) root = tree.getroot() # root = ET.fromstring(xmlContent) dir1_nodes = root.getchildren() # create dir1 for dir1_node in dir1_nodes: dir1 = destDir + os.path.sep + dir1_node.attrib[‘NAME‘] # print dir1 if os.path.exists(dir1) == False: os.mkdir(dir1) # create dir2 dir2_nodes = dir1_node.getchildren() for dir2_node in dir2_nodes: dir2 = dir1 + os.path.sep + dir2_node.attrib[‘NAME‘] if os.path.exists(dir2) == False: os.mkdir(dir2) # create file dir3_nodes = dir2_node.getchildren() for dir3_node in dir3_nodes: dir3 = dir2 + os.path.sep + dir3_node.attrib[‘NAME‘] # 参数w 会新建或覆盖一个文件, f = open(dir3, ‘w‘) # 遍历xml标签name=***.obj prelen = 0 dir4_nodes = dir3_node.getchildren() for dir4_node in dir4_nodes: traversal(dir4_node, f, prelen) f.close() def traversal(node, f, prelen): ‘‘‘‘‘recursively traversal the rest of xml‘s content‘‘‘ length = node.getchildren() attrs = ‘‘ texts = ‘‘ if len(node.attrib) > 0: for key in node.attrib: attrs += str(key) + ":" + str(node.attrib[key]) + " " attrs = attrs[:-1] f.write(‘-‘ * prelen + node.tag + ‘(‘ + attrs + ‘)‘) else: f.write(‘-‘ * prelen + node.tag) if node.text != None: f.write(‘:‘ + node.text) f.write(‘\n‘) if length != 0: nodes = node.getchildren() prelen += 4 for node1 in nodes: traversal(node1, f, prelen) def parseXmls(filePath, destDir): ‘‘‘‘‘traversal xmls directory‘‘‘ if os.path.isfile(filePath) and os.path.basename(filePath).endswith(‘.xml‘): # print ‘filePath===‘,filePath read_xml(filePath, destDir) else: for item in os.listdir(filePath): print item subpath = filePath + os.path.sep + item parseXmls(subpath, destDir) def main(): "Main function." # input xml dir while True: dir = raw_input("input the dir:") if not os.path.exists(dir): print("you input dir is not existed!") continue else: break # create the dir of dest path that using to store the parsing xmls ‘‘‘‘‘destDir = os.path.split(dir)[0]+os.sep+time.strftime(‘%Y%m%d‘) if not os.path.exists(destDir): os.mkdir(destDir) ‘‘‘ destDir = os.path.split(dir)[0] + os.path.sep + os.path.basename(dir) + ‘xml‘ if os.path.exists(destDir) == False: os.mkdir(destDir) # recall the function of parse the xmls parseXmls(dir, destDir) if __name__ == ‘__main__‘: main()
python模块之xml.etree.ElementTree