实例Python处理XML文件的方法

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
写了一个简单的xml，配置需要字段及类型

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"?>


id

query
varchar(200)
false
query

pv
integer
false
pv

avg_money
integer
false

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])

PYTHON解析XML大文件[SAX]
需求
读取xml数据文件，文件较大，需要实时处理插入到数据库

xml文档

 100000
 男
 北京，海淀区
 437
 
1989
 333
 242
 null
 大学
 
 1
 2月14日

处理
sax处理时并不会像dom一样可以以类似节点的维度进行读取,它只有 开始标签 内容 结束标签 之分

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
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 ，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, %s, %s, %s,
 %s, %s, %s, %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, user, pwd, db_name, charset , use_unicode
 self.conn = MySQLdb.Connection(db_host, user, pwd, db_name, 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, 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})

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", "root", "test")
 parseString(f.read().decode("gbk").encode("utf-8"), PersonHandler(db_ops))
 f.close()
 db_ops.close()