python3解析XML文件

软硬件环境

• Ubuntu 15.10 32bit
• Python 3.5.1
• PyQt 5.5.1

前言

Python解析XML的方法挺多，本文主要是利用ElementTree来完成。

实例讲解

解析XML

以如下的XML文件为例

<root>
    <version>1.0.04</version>
    <mysqlhost>10.10.10.240</mysqlhost>
    <mysqlport>3306</mysqlport>
    <mysqluser>root</mysqluser>
    <mysqlpassword>123456</mysqlpassword>
    <mysqldatabase>longjingdb</mysqldatabase>
    <mysqltable>mac</mysqltable>
    <mysqlstbtype>L6000</mysqlstbtype>
    <irdetokeytype>1</irdetokeytype>
    <printerhost>192.168.1.51</printerhost>
    <printerport>4001</printerport>
</root>

编写了一个类来解析，用一个字典来存放

class SYSXMLParser(object):
def __init__(self,file):
    self.xmlFile = file
    self.sysXMLDict = {}

def getSysXMLDict(self):
    tree = ET.parse(self.xmlFile)
    root = tree.getroot()

    for child in root.getchildren():
        self.sysXMLDict[child.tag] = child.attrib
        self.sysXMLDict[child.tag] = child.text

    return self.sysXMLDict

执行后打印的结果如下

{'mysqlstbtype': 'L6000', 'mysqlpassword': '123456', 'version': '1.0.04', 'printerhost': '192.168.1.51', 'printerport': '4001', 'mysqltable': 'mac', 'mysqldatabase': 'longjingdb', 'mysqlport': '3306', 'mysqluser': 'root', 'mysqlhost': '10.10.10.240', 'irdetokeytype': '1'}

创建XML

手头上刚好有个实例，提供一个文件夹，里面是一些烧录镜像文件，针对这个镜像文件夹，需要生成一个XML文件，XML指定各个镜像文件的名字、对应烧录的地址、还有镜像的路径和md5值。

# -*- coding: utf-8 -*-
__author__ = 'djstava@gmail.com'

import os
import sys
import xml.etree.ElementTree as ET

from common.constant import *
from checksum.md5 import *

FirstRoundImages = {'pmp.toc':PMP_ADDRESS,'secboot.toc':SECBOOT_ADDRESS,'secos.toc':SECOS_ADDRESS,'secosbak.toc':SECOS_BACK_ADDRESS,
                'u-boot.toc':UBOOT_ADDRESS,'u-bootbak.toc':UBOOT_BACK_ADDRESS,'splash.dat':SPLASH_ADDRESS}

SecondRoundImages = {'factorytest.img':FACTORYTEST_ADDRESS,'boot.img':BOOT_ADDRESS,'system.img':SYSTEM_ADDRESS,'dvbdata.img':DVBDATA_ADDRESS,
                 'userdata.img':USERDATA_ADDRESS,'cache.img':CACHE_ADDRESS,'otaloader.img':OTALOADER_ADDRESS,'iploader.img':IPLOADER_ADDRESS,
                 'recovery.img':RECOVERY_ADDRESS}

class GenerateConfigXML(object):
    firstRoundImageDict = {}
    secondRoundImageDict = {}

    def __init__(self,path):
        self.path = path

    def buildConfigXML(self):
        '''
        :param path: images dir
        :return:
        '''

        self.listDir(self.path)

        root = ET.Element("root")

        self.firstRound = ET.SubElement(root,"FirstRound")
        for image in self.firstRoundImageDict.keys():
            if image == "pmp.toc":
                imagePmp = ET.SubElement(self.firstRound,image)
                imagePmp.set("name",image)
                imagePmp.set("address",self.firstRoundImageDict[image])
                imagePmp.set("path",os.path.relpath(self.path + "/" + image))
                imagePmp.set("md5",CalcMD5.calcFileMd5(self.path + "/" + image))
                self.firstRoundImageDict.pop(image)
                break

        for image in self.firstRoundImageDict.keys():
            if image == "secboot.toc":
                imagePmp = ET.SubElement(self.firstRound,image)
                imagePmp.set("name",image)
                imagePmp.set("address",self.firstRoundImageDict[image])
                imagePmp.set("path",os.path.relpath(self.path + "/" + image))
                imagePmp.set("md5",CalcMD5.calcFileMd5(self.path + "/" + image))
                self.firstRoundImageDict.pop(image)
                break

        for image in self.firstRoundImageDict.keys():
            if image == "secos.toc":
                imagePmp = ET.SubElement(self.firstRound,image)
                imagePmp.set("name",image)
                imagePmp.set("address",self.firstRoundImageDict[image])
                imagePmp.set("path",os.path.relpath(self.path + "/" + image))
                imagePmp.set("md5",CalcMD5.calcFileMd5(self.path + "/" + image))
                self.firstRoundImageDict.pop(image)
                break

        for image in self.firstRoundImageDict.keys():
            if image == "secosbak.toc":
                imagePmp = ET.SubElement(self.firstRound,image)
                imagePmp.set("name",image)
                imagePmp.set("address",self.firstRoundImageDict[image])
                imagePmp.set("path",os.path.relpath(self.path + "/" + 'secos.toc'))
                imagePmp.set("md5",CalcMD5.calcFileMd5(self.path + "/" + 'secos.toc'))
                self.firstRoundImageDict.pop(image)
                break

        for (name,address) in self.firstRoundImageDict.items():
            if name == "pmp.toc":
                continue

            if name == "u-bootbak.toc":
                imageName = ET.SubElement(self.firstRound,name)
                imageName.set("name",name)
                imageName.set("address",address)
                imageName.set("path",os.path.relpath(self.path + "/u-boot.toc"))
                imageName.set("md5",CalcMD5.calcFileMd5(self.path + "/u-boot.toc"))
                continue

            imageName = ET.SubElement(self.firstRound,name)
            imageName.set("name",name)
            imageName.set("address",address)
            imageName.set("path",os.path.relpath(self.path + "/" + name))
            imageName.set("md5",CalcMD5.calcFileMd5(self.path + "/" + name))

        self.secondRound = ET.SubElement(root,"SecondRound")
        for (name,address) in self.secondRoundImageDict.items():
            imageName = ET.SubElement(self.secondRound,name)
            imageName.set("name",name)
            imageName.set("address",address)
            imageName.set("path",os.path.relpath(self.path + "/" + name))
            imageName.set("md5",CalcMD5.calcFileMd5(self.path + "/" + name))

        tree = ET.ElementTree(root)
        self.indent(root)

        if os.path.exists(XML_CONFIG_FILE):
            os.remove(XML_CONFIG_FILE)

        tree.write("config.xml")

    def listDir(self, path):
        for root,dirs,files in os.walk(path):
            for file in files:
                if file in FirstRoundImages.keys():
                    print("firstRound: " + file)
                    if file == 'secos.toc':
                        self.firstRoundImageDict[file] = FirstRoundImages[file]
                        self.firstRoundImageDict['secosbak.toc'] = FirstRoundImages['secosbak.toc']
                        continue

                    if file == 'u-boot.toc':
                        self.firstRoundImageDict[file] = FirstRoundImages[file]
                        self.firstRoundImageDict['u-bootbak.toc'] = FirstRoundImages['u-bootbak.toc']
                        continue

                    self.firstRoundImageDict[file] = FirstRoundImages[file]

                if file in SecondRoundImages.keys():
                    print("secondRound: " + file)
                    self.secondRoundImageDict[file] = SecondRoundImages[file]

    def indent(self, 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:
                self.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__':
    if len(sys.argv) < 2:
        print("Usage: python3 generateConfigXml.py dirOfTheImages")
        sys.exit(1)

    obj = GenerateConfigXML(sys.argv[1])
    obj.buildConfigXML()

最后生成的config.xml内容如下：

<root>
<FirstRound />
<SecondRound>
    <factorytest.img address="otaloaderbak" md5="2bca7c24acf471ad4126e63224b117c3" name="factorytest.img" path="factory20160411/factorytest.img" />
    <iploader.img address="iploader" md5="40d6bf4fe05bb4ce2d500464d48da5a4" name="iploader.img" path="factory20160411/iploader.img" />
    <boot.img address="boot" md5="b1937b921ee1122f1946dcb96811e69e" name="boot.img" path="factory20160411/boot.img" />
    <system.img address="system" md5="12fe7f8c8920c18a3cc9a815f201cca7" name="system.img" path="factory20160411/system.img" />
    <otaloader.img address="otaloader" md5="0831e96caf91482dbb9efde1ca29d3bd" name="otaloader.img" path="factory20160411/otaloader.img" />
    <userdata.img address="userdata" md5="536d084f75a46470f2373e3052d288dc" name="userdata.img" path="factory20160411/userdata.img" />
</SecondRound>
</root>

最后顺便提供下python3下的MD5计算方法，见下面这个类

# -*- coding: utf-8 -*-
__author__ = 'djstava@gmail.com'

import hashlib

class CalcMD5(object):
def __init__(self):
    pass

@classmethod
def calcFileMd5(self,filePath):
    '''
    :param filePath:
    :return: file checksum value
    '''

    md5 = hashlib.md5()

    fp = open(filePath,'rb')
    md5.update(fp.read())

    while True:
        block = fp.read(1048576)
        if not block:
            break
        md5.update(block)

    fp.close()
    return md5.hexdigest()

@classmethod
def calcStringMd5(self,str):
    '''
    :param str:
    :return: string checksum value
    '''

    return hashlib.md5(str.encode("utf-8")).hexdigest()