使用Python调用Web Service

背景

最近使用GSoap开发了一套基于WebService接口的服务，Java与.Net本身的framework已经集成了WebService的访问组件，C与C++也可以通过GSoap生成客户端代理来访问服务，但是Python本身并没集成WebService的toolkit，下面就Python访问WebService的方法进行介绍。

环境准备

1. 如果python没有安装过setuptool，则需要先下载安装setuptool：
windows下可以从 http://pypi.python.org/packages/2.6/s/setuptools/setuptools-0.6c11.win32-py2.6.exe 获取安装包进行安装；
linux下可以从http://pypi.python.org/packages/source/s/setuptools/setuptools-0.6c11.tar.gz下载tar包进行源码安装：

tar zxvf setuptools-0.6c11.tar.gz cd setuptools-0.6c11 python setup.py build python setup.py install

如果是ubuntu或者redhat等系统，也可以使用apt或者rpm方式安装，这里不过多说明，安装过程中可能需要root权限。

2. 检查python中是否安装了suds，在python（version 2.6）交互模式下调用：
>>> from suds.client import Client

如果显示“No module named **”，则表名没有安装过suds，可以从https://fedorahosted.org/suds/ 获取源码包或者rpm包进行安装，下面介绍一下源码包安装的方法：

tar zxf python-suds-0.4.tar.gz cd  python-suds-0.4 python setup.py install

同样的，如果python安装在系统目录下，则可能需要root权限。

WebService接口

我本次开发的是一个类似于监控系统，在局域网中有多台主机上安装了probe agent，它们负责收集与回传数据，有一台总控的monitor server，它负责接收用户的Web Service请求，根据请求选择一台或多台probe agent，让其定时收集指定的数据，如cpu空闲率等。monitor server的接口比较简单，主要就是 StartTask，StopTask与DeleteTask，它的WSDL定义如下：

<?xml version="1.0" encoding="UTF-8"?>
<definitions name="MonitorServer"
targetNamespace="http://www.baidu.com/dsqa/webservices/"
xmlns:tns="http://www.baidu.com/dsqa/webservices/"
xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"
xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:ns="http://www.myserver.com/webservices/"
xmlns:SOAP="http://schemas.xmlsoap.org/wsdl/soap/"
xmlns:MIME="http://schemas.xmlsoap.org/wsdl/mime/"
xmlns:DIME="http://schemas.xmlsoap.org/ws/2002/04/dime/wsdl/"
xmlns:WSDL="http://schemas.xmlsoap.org/wsdl/"
xmlns="http://schemas.xmlsoap.org/wsdl/">

<types>

<schema targetNamespace="http://www.baidu.com/dsqa/webservices/"
xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"
xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:ns="http://www.myserver.com/webservices/"
xmlns="http://www.w3.org/2001/XMLSchema"
elementFormDefault="unqualified"
attributeFormDefault="unqualified">
<import namespace="http://schemas.xmlsoap.org/soap/encoding/"/>
<complexType name="HostEntry"><!-- ns__HostEntry -->

<sequence>
<element name="Endpoint" type="xsd:string" minOccurs="1" maxOccurs="1"/><!-- ns__HostEntry::Endpoint -->
</sequence>
</complexType>
<complexType name="MonitorEntry"><!-- ns__MonitorEntry -->

<sequence>
<element name="Name" type="xsd:string" minOccurs="1" maxOccurs="1"/><!-- ns__MonitorEntry::Name -->
<element name="Description" type="xsd:string" minOccurs="1" maxOccurs="1" default=""/><!-- ns__MonitorEntry::Description -->
<element name="ValueType" type="xsd:int" minOccurs="1" maxOccurs="1"/><!-- ns__MonitorEntry::ValueType -->
<element name="Interval" type="xsd:unsignedInt" minOccurs="1" maxOccurs="1"/><!-- ns__MonitorEntry::Interval -->
<element name="Extra" type="xsd:string" minOccurs="1" maxOccurs="1" default=""/><!-- ns__MonitorEntry::Extra -->
<element name="Consolidate" type="xsd:int" minOccurs="1" maxOccurs="1" default="0"/><!-- ns__MonitorEntry::Consolidate -->
<element name="Hosts" type="xsd:unsignedLong" minOccurs="0" maxOccurs="unbounded"/><!-- ns__MonitorEntry::Hosts -->
</sequence>
</complexType>
<complexType name="HostArray"><!-- ns__HostArray -->

<sequence>
<element name="Items" type="ns:HostEntry" minOccurs="0" maxOccurs="unbounded" nillable="true"/>
</sequence>
</complexType>
<complexType name="MonitorArray"><!-- ns__MonitorArray -->

<sequence>
<element name="Items" type="ns:MonitorEntry" minOccurs="0" maxOccurs="unbounded" nillable="true"/>
</sequence>
</complexType>
<complexType name="StartRequest"><!-- ns__StartRequest -->

<sequence>
<element name="User" type="xsd:string" minOccurs="1" maxOccurs="1" default="anonymous"/><!-- ns__StartRequest::User -->
<element name="Description" type="xsd:string" minOccurs="1" maxOccurs="1" default=""/><!-- ns__StartRequest::Description -->
<element name="MaxProbeTime" type="xsd:dateTime" minOccurs="1" maxOccurs="1"/><!-- ns__StartRequest::MaxProbeTime -->
<element name="MaxKeepTime" type="xsd:dateTime" minOccurs="1" maxOccurs="1"/><!-- ns__StartRequest::MaxKeepTime -->
<element name="Force" type="xsd:int" minOccurs="1" maxOccurs="1" default="0"/><!-- ns__StartRequest::Force -->
<element name="Hosts" type="ns:HostArray" minOccurs="1" maxOccurs="1" nillable="true"/><!-- ns__StartRequest::Hosts -->
<element name="Monitors" type="ns:MonitorArray" minOccurs="1" maxOccurs="1" nillable="true"/><!-- ns__StartRequest::Monitors -->
</sequence>
</complexType>
<complexType name="StopRequest"><!-- ns__StopRequest -->

<sequence>
<element name="User" type="xsd:string" minOccurs="1" maxOccurs="1"/><!-- ns__StopRequest::User -->
<element name="TaskId" type="xsd:unsignedLong" minOccurs="1" maxOccurs="1"/><!-- ns__StopRequest::TaskId -->
</sequence>
</complexType>
<complexType name="DeleteRequest"><!-- ns__DeleteRequest -->

<sequence>
<element name="User" type="xsd:string" minOccurs="1" maxOccurs="1"/><!-- ns__DeleteRequest::User -->
<element name="TaskId" type="xsd:unsignedLong" minOccurs="1" maxOccurs="1"/><!-- ns__DeleteRequest::TaskId -->
</sequence>
</complexType>
<!-- operation request element -->
<element name="StartTask">
<complexType>
<sequence>
<element name="request" type="ns:StartRequest" minOccurs="0" maxOccurs="1" nillable="true"/><!-- ns__StartTask::request -->
</sequence>
</complexType>
</element>
<!-- operation response element -->
<element name="StartResponse">
<complexType>
<sequence>
<element name="ErrCode" type="xsd:int" minOccurs="1" maxOccurs="1"/><!-- ns__StartResponse::ErrCode -->
<element name="ErrMsg" type="xsd:string" minOccurs="1" maxOccurs="1"/><!-- ns__StartResponse::ErrMsg -->
<element name="TaskId" type="xsd:unsignedLong" minOccurs="1" maxOccurs="1"/><!-- ns__StartResponse::TaskId -->
</sequence>
</complexType>
</element>
<!-- operation request element -->
<element name="StopTask">
<complexType>
<sequence>
<element name="request" type="ns:StopRequest" minOccurs="0" maxOccurs="1" nillable="true"/><!-- ns__StopTask::request -->
</sequence>
</complexType>
</element>
<!-- operation response element -->
<element name="StopResponse">
<complexType>
<sequence>
<element name="ErrCode" type="xsd:int" minOccurs="1" maxOccurs="1"/><!-- ns__StopResponse::ErrCode -->
<element name="ErrMsg" type="xsd:string" minOccurs="1" maxOccurs="1"/><!-- ns__StopResponse::ErrMsg -->
</sequence>
</complexType>
</element>
<!-- operation request element -->
<element name="DeleteTask">
<complexType>
<sequence>
<element name="request" type="ns:DeleteRequest" minOccurs="0" maxOccurs="1" nillable="true"/><!-- ns__DeleteTask::request -->
</sequence>
</complexType>
</element>
<!-- operation response element -->
<element name="DeleteResponse">
<complexType>
<sequence>
<element name="ErrCode" type="xsd:int" minOccurs="1" maxOccurs="1"/><!-- ns__DeleteResponse::ErrCode -->
<element name="ErrMsg" type="xsd:string" minOccurs="1" maxOccurs="1"/><!-- ns__DeleteResponse::ErrMsg -->
</sequence>
</complexType>
</element>
</schema>

</types>

<message name="StartTask">
<part name="parameters" element="ns:StartTask"/><!-- ns__StartTask::ns__StartTask -->
</message>

<message name="StartResponse">
<part name="parameters" element="ns:StartResponse"/><!-- ns__StartTask::resopne -->
</message>

<message name="StopTask">
<part name="parameters" element="ns:StopTask"/><!-- ns__StopTask::ns__StopTask -->
</message>

<message name="StopResponse">
<part name="parameters" element="ns:StopResponse"/><!-- ns__StopTask::response -->
</message>

<message name="DeleteTask">
<part name="parameters" element="ns:DeleteTask"/><!-- ns__DeleteTask::ns__DeleteTask -->
</message>

<message name="DeleteResponse">
<part name="parameters" element="ns:DeleteResponse"/><!-- ns__DeleteTask::response -->
</message>

<portType name="MonitorServerPortType">
<operation name="StartTask">
<documentation>Service definition of function ns__StartTask</documentation>
<input message="tns:StartTask"/>
<output message="tns:StartResponse"/>
</operation>
<operation name="StopTask">
<documentation>Service definition of function ns__StopTask</documentation>
<input message="tns:StopTask"/>
<output message="tns:StopResponse"/>
</operation>
<operation name="DeleteTask">
<documentation>Service definition of function ns__DeleteTask</documentation>
<input message="tns:DeleteTask"/>
<output message="tns:DeleteResponse"/>
</operation>
</portType>

<binding name="MonitorServer" type="tns:MonitorServerPortType">
<SOAP:binding style="document" transport="http://schemas.xmlsoap.org/soap/http"/>
<operation name="StartTask">
<SOAP:operation soapAction=""/>
<input>
<SOAP:body parts="parameters" use="literal"/>
</input>
<output>
<SOAP:body parts="parameters" use="literal"/>
</output>
</operation>
<operation name="StopTask">
<SOAP:operation soapAction=""/>
<input>
<SOAP:body parts="parameters" use="literal"/>
</input>
<output>
<SOAP:body parts="parameters" use="literal"/>
</output>
</operation>
<operation name="DeleteTask">
<SOAP:operation soapAction=""/>
<input>
<SOAP:body parts="parameters" use="literal"/>
</input>
<output>
<SOAP:body parts="parameters" use="literal"/>
</output>
</operation>
</binding>

<service name="MonitorServer">
<documentation>gSOAP 2.8.4 generated service definition</documentation>
<port name="MonitorServer" binding="tns:MonitorServer">
<SOAP:address location="http://host:port"/>
</port>
</service>

</definitions>

Python调用

#导入suds包
from suds.client import Client
from datetime import *

#WSDL文件的Location
url =  "http://host:port/service.wsdl"
#根据wsdl创建一个WebService的Client
client = Client(url)
request1 = client.factory.create('StartRequest')
request1.User="mycustomer"
request1.Description="test case"
request1.Force=1
#添加一台监控机器
host1 = client.factory.create('HostEntry')
host1.Endpoint='http://myprobe_address'
request1.Hosts.Items.append(host1)

#添加一个监控项
monitor1 = client.factory.create('MonitorEntry')
monitor1.Name='sys.cpu.idle_rate'
monitor1.ValueType=1
monitor1.Interval=1
monitor1.Extra=""
monitor1.Description="perf1"
monitor1.Consolidate=0
monitor1.Hosts.append(0)
request1.Monitors.Items.append(monitor1)
#请求
request1.MaxKeepTime = datetime.now() + timedelta(seconds=3600)
request1.MaxProbeTime = datetime.now() + timedelta(seconds=60)
response1 = client.service.StartTask(request1)
print response1
#检查响应
if response1.ErrCode != 0:
print response1.ErrMsg
else:
task = response1.TaskId

#停止任务
request2 = client.factory.create('StopRequest')
request2.TaskId=task
response2 = client.service.StopTask(request2)
if response2.ErrCode != 0:
print response2.ErrMsg

#删除任务
request3 = client.factory.create('DeleteRequest')
request3.TaskId=task
response3 = client.service.DeleteTask(request3)
if response2.ErrCode != 0:
print response2.ErrMsg

其他

其他几种使用python调用web service的方法：http://pywebsvcs.sourceforge.net/
一些公共的WebService：http://www.webxml.com.cn/zh_cn/web_services.aspx
作者：icefireelf
出处：http://blog.csdn.net/icefireelf/article/details/7264141