[zz]使用Python读写XML文件

来源： http://lulinbest.blog.sohu.com/75921823.html

以前用Python中的minidom写过生成XML文件的程序,现在需要读取XML文件中的内容了，首先想到的还是minidom模块.一番编写测试后,如愿掌握了其函数的使用方式,和AJAX中的DOM操作没什么区别.

  以前就知道elementtree在处理XML文件时广受Python程序员的欢迎,也安装过elementtree的安装包,现在使用的Python2.5中已将其收录了.既然我要处理XML文件，当然也要学着使用更高效和易用的模块了.自己摸索了半天,除了有关名字空间的函数没有试用外,其它函数都试用过了.以后处理XML文件可以得心应手了。

下面是一个简单的例子,通过它可以知道各个函数的使用方法：
 

from xml.etree.ElementTree import ElementTree
from xml.etree.ElementTree import Element
from xml.etree.ElementTree import SubElement
from xml.etree.ElementTree import dump
from xml.etree.ElementTree import Comment
from xml.etree.ElementTree import tostring

'''


  
  
    Potato Smasher
    Smash Potatoes like never before.
  

'''

## Writing the content to xml document
book = ElementTree()

purchaseorder = Element('PurchaseOrder')
book._setroot(purchaseorder)

SubElement(purchaseorder,  'account', {'refnum' : "2390094"})

item = Element("item", {'sku' : '33-993933', 'qty' : '4'})
purchaseorder.append(item)
print item.items()       # [('sku', '33-993933'), ('qty', '4')]
print item.attrib        # {'sku': '33-993933', 'qty': '4'}
print item.get('sku')    # 33-993933
SubElement(item, 'name').text = "Potato Smasher"
SubElement(item, 'description').text = "Smash Potatoes like never before."

#book.write('book.xml',"utf-8")

#print tostring(purchaseorder)

#import sys
#book.write(sys.stdout)

#dump(book)

## Displaying the content of the xml document
print purchaseorder.find('account')
print purchaseorder.find('account').get('refnum')
print purchaseorder.findall('account')[0].get('refnum')

print purchaseorder.find('item/name')
print purchaseorder.find('item/name').text

## How to use ElementTree([element,] [file])
## 1. From standard XML element, it becomes root element
print ElementTree(item).getroot().find('name').text
## 2. From XML file
print ElementTree(file='book.xml').getroot().find('item/description').text


## Create an iterator
for element in purchaseorder.getiterator():
    print element.tag


## Get pretty look
def indent(elem, level=0):
    i = "\n" + level*"  "
    if len(elem):
        if not elem.text or not elem.text.strip():
            elem.text = i + "  "
        for e in elem:
            indent(e, level+1)
        if not e.tail or not e.tail.strip():
            e.tail = i
    if level and (not elem.tail or not elem.tail.strip()):
        elem.tail = i
    return elem

if __name__=="__main__":
    dump(indent(purchaseorder))
    book.write('book.xml',"utf-8")