Python解析xml文档实例

使用Python

用到的包：xml.dom.minidom

需求：

有一个表，里面数据量比较大，每天一更新，其字段可以通过配置文件进行配置，即，可能每次建表的字段不一样。

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"?>
<table name="top_query" db_name="evaluting_sys">
<primary_key>
<name>id</name>
</primary_key>
<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>
</table>

脚本：

#!/usr/bin/python
# -*- coding:utf-8 -*-
#author: ken
#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(<span style="background-color: rgb(255, 255, 255); ">xml_file_path)</span>
table = root.getElementsByTagName("table")[0]
#read dbname and table name.
tabletable_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_keyprimary_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 = minidom.parse(xml_file_path) 获取dom对象

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（<name>id</name> 得到id）

-----------------------------------------------------

简单的读取就是这样，这里只是简单使用了下

后续需去了解下python读取xml的几个库

xml.dom.minidom

xml.etree.ElementTree

libxml2

lxml.etree

xpath

Python解析xml文档实例

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