Python通过DOM和SAX方式解析XML的应用实例分享
XML.DOM 需求 上游跑时会根据配置从源文件中提取,到入库这一步需要根据配置进行建表。 解决 上游读取到对应的数据 入库这一步,先把原表删除,根据配置建新表 XML文件 <?xml version="1.0" encoding="UTF-8"?> <!-- 表名,数据库名 可灵活配置插入哪个库哪个表 --> <table name="top_query" db_name="evaluting_sys"> <!-- 非业务主键,自增长,可配名,其他 INTEGER UNSIGNED AUTO_INCREMENT --> <primary_key> <name>id</name> </primary_key> <!-- 字段开始 --> <field> <name>query</name> <type>varchar(200)</type> <is_index>false</is_index> <description>query</description> </field> <field> <name>pv</name> <type>integer</type> <is_index>false</is_index> <description>pv</description> </field> <field> <name>avg_money</name> <type>integer</type> <is_index>false</is_index> <description></description> </field> <!-- 字段配置结束 --> </table> 处理脚本 #!/usr/bin/python # -*- coding:utf-8 -*- #author: wklken #desc: use to read db xml config. #----------------------- #2012-02-18 created #---------------------- import sys,os from xml.dom import minidom,Node def read_dbconfig_xml(xml_file_path): content = {} root = minidom.parse(xml_file_path) table = root.getElementsByTagName("table")[0] #read dbname and table name. table_name = table.getAttribute("name") db_name = table.getAttribute("db_name") if len(table_name) > 0 and len(db_name) > 0: db_sql = "create database if not exists `" + db_name +"`; use " + db_name + ";" table_drop_sql = "drop " + table_name + " if exists " + table_name + ";" content.update({"db_sql" : db_sql}) content.update({"table_sql" : table_drop_sql }) else: print "Error:attribute is not define well! db_name=" + db_name + " ;table_name=" + table_name sys.exit(1) #print table_name,db_name table_create_sql = "create table " + table_name +"(" #read primary cell primary_key = table.getElementsByTagName("primary_key")[0] primary_key_name = primary_key.getElementsByTagName("name")[0].childNodes[0].nodeValue table_create_sql += primary_key_name + " INTEGER NOT NULL AUTO_INCREMENT PRIMARY KEY," #print primary_key.toxml() #read ordernary field fields = table.getElementsByTagName("field") f_index = 0 for field in fields: f_index += 1 name = field.getElementsByTagName("name")[0].childNodes[0].nodeValue type = field.getElementsByTagName("type")[0].childNodes[0].nodeValue table_create_sql += name + " " + type if f_index != len(fields): table_create_sql += "," is_index = field.getElementsByTagName("is_index")[0].childNodes[0].nodeValue table_create_sql += ");" content.update({"table_create_sql" : table_create_sql}) #character set latin1 collate latin1_danish_ci; print content if __name__ == "__main__": read_dbconfig_xml(sys.argv[1]) 涉及方法 root.getElementsByTagName("table") 根据tag获取节点列表 table.getAttribute("name") 获取属性 primary_key.getElementsByTagName("name")[0].childNodes[0].nodeValue 获取子节点的值(id 得到id)
xml文档 <PERSONS> <person> <id>100000</id> <sex>男</sex> <address>北京,海淀区</address> <fansNum>437</fansNum> <summary>1989</summary> <wbNum>333</wbNum> <gzNum>242</gzNum> <blog>null</blog> <edu>大学</edu> <work></work> <renZh>1</renZh> <brithday>2月14日</brithday> </person> </PERSONS> 处理 处理思想是:通过一个handler,对开始标签,内容,结束标签各有一个处理函数 代码及注解 from xml.sax import handler,parseString class PersonHandler(handler.ContentHandler): def __init__(self,db_ops): #db op obj self.db_ops = db_ops #存储一个person的map self.person = {} #当前的tag self.current_tag = "" #是否是tag之间的内容 ,目的拿到tag间内容,不受空白的干扰 self.in_quote = 0 #开始,清空map def startElement(self,name,attr): #以person,清空map if name == "person": self.person = {} #记录 状态 self.current_tag = name self.in_quote = 1 #结束,插入数据库 def endElement(self,name): #以person结尾 代表读取一个person的信息结束 if name == "person": #do something in_fields = tuple([ ('"' + self.person.get(i,"") + '"') for i in fields ]) print in_sql % in_fields db_ops.insert( in_sql%(in_fields)) #处理 self.in_quote = 0 def characters(self,content): #若是在tag之间的内容,更新到map中 if self.in_quote: self.person.update({self.current_tag: content}) 加上入库的完整代码 #!/usr/bin/python # -*- coding:utf-8 -*- #parse_person.py #version : 0.1 #author : wukunliang@163.com #desc : parse person.xml and out sql import sys,os import MySQLdb reload(sys) sys.setdefaultencoding('utf-8') in_sql = "insert into person(id,sex,address,fansNum,summary,wbNum,gzNum,blog,edu,work,renZh,brithday) values(%s,%s,%s)" fields = ("id","sex","address","fansNum","summary","wbNum","gzNum","blog","edu","work","renZh","brithday") #数据库方法 class Db_Connect: def __init__(self,db_host,user,pwd,db_name,charset="utf8",use_unicode = True): print "init begin" print db_host,charset,use_unicode self.conn = MySQLdb.Connection(db_host,charset=charset,use_unicode=use_unicode) print "init end" def insert(self,sql): try: n = self.conn.cursor().execute(sql) return n except MySQLdb.Warning,e: print "Error: execute sql '",sql,"' failed" def close(self): self.conn.close() #person 处理类 from xml.sax import handler,parseString class PersonHandler(handler.ContentHandler): def __init__(self,db_ops): #db op obj self.db_ops = db_ops #存储一个person的map self.person = {} #当前的tag self.current_tag = "" #是否是tag之间的内容 self.in_quote = 0 #开始,清空map def startElement(self,attr): #以person,清空map if name == "person": self.person = {} #记录 状态 self.current_tag = name self.in_quote = 1 #结束,插入数据库 def endElement(self,name): #以person结尾 代表读取一个person的信息结束 if name == "person": #do something in_fields = tuple([ ('"' + self.person.get(i,"") + '"') for i in fields ]) print in_sql % in_fields db_ops.insert( in_sql%(in_fields)) #处理 self.in_quote = 0 def characters(self,content): #若是在tag之间的内容,更新到map中 if self.in_quote: self.person.update({self.current_tag: content}) if __name__ == "__main__": f = open("./person.xml") #如果源文件gbk 转码 若是utf-8,去掉decode.encode db_ops = Db_Connect("127.0.0.1","root","test") parseString(f.read().decode("gbk").encode("utf-8"),PersonHandler(db_ops)) f.close() db_ops.close() 平时拿python来分析数据,工具脚本还有hadoop streamming,但是用的面和深度实在欠缺 只能说道行还浅,需要多多实践 (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |