以country.xml為例,內(nèi)容如下:

<?xml version='1.0'?><data> <country name='Liechtenstein'> <rank updated='yes'>2</rank> <year>2008</year> <gdppc>141100</gdppc> <neighbor name='Austria' direction='E'/> <neighbor name='Switzerland' direction='W'/> </country> <country name='Singapore'> <rank updated='yes'>5</rank> <year>2011</year> <gdppc>59900</gdppc> <neighbor name='Malaysia' direction='N'/> </country> <country name='Panama'> <rank updated='yes'>69</rank> <year>2011</year> <gdppc>13600</gdppc> <neighbor name='Costa Rica' direction='W'/> <neighbor name='Colombia' direction='E'/> </country></data>

1.解析

1)調(diào)用parse()方法，返回解析樹

try: import xml.etree.cElementTree as ETexcept ImportError: import xml.etree.ElementTree as ETtree = ET.parse('country.xml') # <class ’xml.etree.ElementTree.ElementTree’>root = tree.getroot() # 獲取根節(jié)點 <Element ’data’ at 0x02BF6A80>

2)調(diào)用from_string(),返回解析樹的根元素

import xml.etree.ElementTree as ETdata = open('country.xml').read()root = ET.fromstring(data) # <Element ’data’ at 0x036168A0>

3)調(diào)用ElementTree類ElementTree(self, element=None, file=None) # 這里的element作為根節(jié)點

import xml.etree.ElementTree as ETtree = ET.ElementTree(file='country.xml') # <xml.etree.ElementTree.ElementTree object at 0x03031390>root = tree.getroot() # <Element ’data’ at 0x030EA600>

1)簡單遍歷

import xml.etree.ElementTree as ETtree = ET.parse('country.xml')root = tree.getroot()print(root.tag, ':', root.attrib) # 打印根元素的tag和屬性# 遍歷xml文檔的第二層for child in root: # 第二層節(jié)點的標(biāo)簽名稱和屬性 print(child.tag,':', child.attrib) # 遍歷xml文檔的第三層 for children in child: # 第三層節(jié)點的標(biāo)簽名稱和屬性 print(children.tag, ':', children.attrib)

可以通過下標(biāo)的方式直接訪問節(jié)點

# 訪問根節(jié)點下第一個country的第二個節(jié)點year,獲取對應(yīng)的文本year = root[0][1].text # 2008

2)ElementTree提供的方法

find(match) # 查找第一個匹配的子元素， match可以時tag或是xpaht路徑findall(match) # 返回所有匹配的子元素列表findtext(match, default=None) # iter(tag=None) # 以當(dāng)前元素為根節(jié)點 創(chuàng)建樹迭代器,如果tag不為None,則以tag進(jìn)行過濾iterfind(match) #

例子:

# 過濾出所有neighbor標(biāo)簽for neighbor in root.iter('neighbor'):print(neighbor.tag, ':', neighbor.attrib)

# 遍歷所有的counry標(biāo)簽for country in root.findall('country'):# 查找country標(biāo)簽下的第一個rank標(biāo)簽rank = country.find('rank').text# 獲取country標(biāo)簽的name屬性name = country.get('name')print(name, rank)

1) 屬性相關(guān)

# 將所有的rank值加1,并添加屬性updated為yesfor rank in root.iter('rank'): new_rank = int(rank.text) + 1 rank.text = str(new_rank) # 必須將int轉(zhuǎn)為str rank.set('updated', 'yes') # 添加屬性# 再終端顯示整個xmlET.dump(root)# 注意 修改的內(nèi)容存在內(nèi)存中 尚未保存到文件中# 保存修改后的內(nèi)容tree.write('output.xml')

import xml.etree.ElementTree as ETtree = ET.parse('output.xml')root = tree.getroot()for rank in root.iter('rank'): # attrib為屬性字典 # 刪除對應(yīng)的屬性updated del rank.attrib[’updated’] ET.dump(root)

小結(jié): 關(guān)于classxml.etree.ElementTree.Element 屬性相關(guān)

attrib 為包含元素屬性的字典 keys() 返回元素屬性名稱列表 items() 返回(name,value)列表 get(key, default=None) 獲取屬性 set(key, value) # 跟新/添加 屬性 del xxx.attrib[key] # 刪除對應(yīng)的屬性

2) 節(jié)點/元素 相關(guān)

刪除子元素remove()

import xml.etree.ElementTree as ETtree = ET.parse('country.xml')root = tree.getroot()# 刪除rank大于50的國家for country in root.iter('country'): rank = int(country.find('rank').text) if rank > 50: # remove()方法 刪除子元素 root.remove(country)ET.dump(root)

添加子元素

代碼:

import xml.etree.ElementTree as ETtree = ET.parse('country.xml')root = tree.getroot()country = root[0]last_ele = country[len(list(country))-1]last_ele.tail = ’ntt’# 創(chuàng)建新的元素, tag為test_appendelem1 = ET.Element('test_append')elem1.text = 'elem 1'# elem.tail = ’nt’country.append(elem1)# SubElement() 其實內(nèi)部調(diào)用的時append()elem2 = ET.SubElement(country, 'test_subelement')elem2.text = 'elem 2'# extend()elem3 = ET.Element('test_extend')elem3.text = 'elem 3'elem4 = ET.Element('test_extend')elem4.text = 'elem 4'country.extend([elem3, elem4])# insert()elem5 = ET.Element('test_insert')elem5.text = 'elem 5'country.insert(5, elem5)ET.dump(country)

效果:

添加子元素方法總結(jié):

append(subelement) extend(subelements) insert(index, element)

4.創(chuàng)建xml文檔

想創(chuàng)建root Element,然后創(chuàng)建SubElement,最后將root element傳入ElementTree(element),創(chuàng)建tree，調(diào)用tree.write()方法寫入文件

對于創(chuàng)建元素的3個方法: 使用ET.Element、Element對象的makeelement()方法以及ET.SubElement

import xml.etree.ElementTree as ETdef subElement(root, tag, text): ele = ET.SubElement(root, tag) ele.text = text ele.tail = ’n’root = ET.Element('note')to = root.makeelement('to', {})to.text = 'peter'to.tail = ’n’root.append(to)subElement(root, 'from', 'marry')subElement(root, 'heading', 'Reminder')subElement(root, 'body', 'Don’t forget the meeting!')tree = ET.ElementTree(root)tree.write('note.xml', encoding='utf-8', xml_declaration=True)

效果:

由于原生保存的XML時默認(rèn)無縮進(jìn)，如果想要設(shè)置縮進(jìn)的話， 需要修改保存方式

代碼:

import xml.etree.ElementTree as ETfrom xml.dom import minidomdef subElement(root, tag, text): ele = ET.SubElement(root, tag) ele.text = textdef saveXML(root, filename, indent='t', newl='n', encoding='utf-8'): rawText = ET.tostring(root) dom = minidom.parseString(rawText) with open(filename, ’w’) as f: dom.writexml(f, '', indent, newl, encoding)root = ET.Element('note')to = root.makeelement('to', {})to.text = 'peter'root.append(to)subElement(root, 'from', 'marry')subElement(root, 'heading', 'Reminder')subElement(root, 'body', 'Don’t forget the meeting!')# 保存xml文件saveXML(root, 'note.xml')

以上就是本文的全部內(nèi)容，希望對大家的學(xué)習(xí)有所幫助，也希望大家多多支持好吧啦網(wǎng)。