序言

web services 已经不再流行，但是，由于它的在接口技术中有着非常重要的地位，同时现在最主要的Web 服务设计模型REST其实也属于web services 技术范畴。所以我们还是有必要学习一下。

其实 Web Serive 是一项不太容易讲清楚技术。他的相关概念包括：

SOA Service-Oriented Architecture
Web Services
SOAP (Simple Object Access Protocol)
WSDL (Web Services Description Language)
UDDI (Universal Description Discovery and Integration)

环境搭建

python 使用简单，第三方库丰富，我们搭建好环境，进行一整套web services 程序的开发。

我们使用 python 3.6 这个较新python 版本

创建conda 环境

conda create --name Web_Services python=3.6
conda activate Web_Services

导出依赖包

pip freeze > requirements.txt
conda list -e > requirements.txt

依赖包列表

# This file may be used to create an environment using:
# $ conda create --name <env> --file <this file>
# platform: win-64
certifi=2019.6.16=py36_0
lxml=4.3.4=pypi_0
pip=19.1.1=py36_0
python=3.6.8=h9f7ef89_7
pytz=2019.1=pypi_0
setuptools=41.0.1=py36_0
spyne=2.12.16=pypi_0
sqlite=3.28.0=he774522_0
suds-py3=1.3.3.0=pypi_0
vc=14.1=h0510ff6_4
vs2015_runtime=14.15.26706=h3a45250_4
wheel=0.33.4=py36_0
wincertstore=0.2=py36h7fe50ca_0

使用conda 或者pip 批量安装

pip install -r requirements.txt
conda install --yes --file requirements.txt

在这里插入图片描述
但是注意，async=False ，这个参数问题在3.7版本中有问题，spyne 库会有报错。因为在Python3.7里async变成了关键字，关键字是不能做变量名的，只要把这个名字改成任意不是关键字的词就好了。

服务端开发

针对Python的WebService开发，最早开发者使用最多的库是soaplib（官方地址：http://soaplib.github.io/soaplib/2_0/index.html ），
但从其官网可知，其最新版本“soaplib-2.0.0-beta2”从2011年3月发布后就不再进行更新了。

通过阅读soaplib的官方文档，可知其不再维护后已经转向了一个新的项目：rpclib（官方地址：http://github.com/arskom/rpclib ）进行后续开发，但在rpclib的readme中，介绍了rpclib已经更名为spyne，并将持续进行更新。

综上，所以选用spyne进行开发了。

服务端样例代码:

https://github.com/arskom/spyne/blob/master/examples/helloworld_soap.py

#!/usr/bin/env python
# -*- encoding: utf-8 -*-
#-------------------------------------------------------------------------------
'''
@Author  :   {SEASON}
@License :   (C) Copyright 2013-2022, {OLD_IT_WANG}
@Contact :   {}
@Software:   PyCharm
@File    :   Web_Services_Test20190708 -- Web_Services
@Time    :   2019/7/11 9:03
@Desc    :

'''
#-------------------------------------------------------------------------------
# !/usr/bin/env python
# -*- coding: utf-8 -*-

"""
preference:
    http://spyne.io/docs/2.10/index.html
    https://github.com/arskom/spyne/blob/master/examples/helloworld_soap.py

This is a simple HelloWorld example to show the basics of writing
a webservice using spyne, starting a server, and creating a service
client.
Here's how to call it using suds:

#>>> from suds.client import Client
#>>> hello_client = Client('http://localhost:8000/?wsdl')
#>>> hello_client.service.say_hello('punk', 5)
(stringArray){
   string[] =
      "Hello, punk",
      "Hello, punk",
      "Hello, punk",
      "Hello, punk",
      "Hello, punk",
 }
#>>>

"""
# Application is the glue between one or more service definitions, interface and protocol choices.
from spyne import Application
# @rpc decorator exposes methods as remote procedure calls
# and declares the data types it accepts and returns
from spyne import rpc
# spyne.service.ServiceBase is the base class for all service definitions.
from spyne import ServiceBase
# The names of the needed types for implementing this service should be self-explanatory.
from spyne import Iterable, Integer, Unicode

from spyne.protocol.soap import Soap11
# Our server is going to use HTTP as transport, It’s going to wrap the Application instance.
from spyne.server.wsgi import WsgiApplication


# step1: Defining a Spyne Service
class HelloWorldService(ServiceBase):
    @rpc(Unicode, Integer, _returns=Iterable(Unicode))
    def say_hello(self, name, times):
        """Docstrings for service methods appear as documentation in the wsdl.
        <b>What fun!</b>
        @param name: the name to say hello to
        @param times: the number of times to say hello
        @return  When returning an iterable, you can use any type of python iterable. Here, we chose to use generators.
        """

        for i in range(times):
            yield u'Hello, %s' % name


# step2: Glue the service definition, input and output protocols
soap_app = Application([HelloWorldService], 'spyne.examples.hello.soap',
                       in_protocol=Soap11(validator='lxml'),
                       out_protocol=Soap11())

# step3: Wrap the Spyne application with its wsgi wrapper
wsgi_app = WsgiApplication(soap_app)

if __name__ == '__main__':
    import logging

    from wsgiref.simple_server import make_server

    # configure the python logger to show debugging output
    logging.basicConfig(level=logging.DEBUG)
    logging.getLogger('spyne.protocol.xml').setLevel(logging.DEBUG)

    logging.info("listening to http://127.0.0.1:8000")
    logging.info("wsdl is at: http://localhost:8000/?wsdl")

    # step4:Deploying the service using Soap via Wsgi
    # register the WSGI application as the handler to the wsgi server, and run the http server
    server = make_server('127.0.0.1', 8000, wsgi_app)
    server.serve_forever()

客户端开发

这方面有两个python 组件可以使用，分别是：

suds-jurko
suds-py3

suds-jurko

pip install suds-jurko

文档
https://bitbucket.org/jurko/suds/wiki/Original%20Documentation

suds-py3

https://github.com/cackharot/suds-py3

pip3 install suds-py3

客户端样例代码

#!/usr/bin/env python
# -*- encoding: utf-8 -*-
#-------------------------------------------------------------------------------
'''
@Author  :   {SEASON}
@License :   (C) Copyright 2013-2022, {OLD_IT_WANG}
@Contact :   {shiter@live.cn}
@Software:   PyCharm
@File    :   Web_Services_Test20190708 -- test_client_suds-py3_eg
@Time    :   2019/7/11 23:45
@Desc    :

'''
#-------------------------------------------------------------------------------


import sys
import os
suds_path = os.path.realpath(os.path.join(os.path.dirname(__file__), '..'))
sys.path.append(suds_path)

from suds.client import Client

def set_log():
    import logging
    logging.basicConfig(level=logging.INFO)
    logging.getLogger('suds.client').setLevel(logging.DEBUG)
    logging.getLogger('suds.transport').setLevel(logging.DEBUG)
    # logging.getLogger('suds.xsd.schema').setLevel(logging.DEBUG)

def call_service(url):
    client = Client(url, username='bob', password='catbob')
    do_call_service(client, url)

def do_call_service(client, url):
    print("Calling: sayHello()")
    result = client.service.sayHello('Username')

    print("Result: %s" % result)
    a = 10.98
    b = 98.83
    print("Calling: add()")
    sum = client.service.add(a, b)
    print("Result: Sum of %f + %f = %f" % (a,b,sum))

    print("Calling: addDate()")
    from datetime import datetime
    import time
    inputDate = datetime.now()
    dt = client.service.addDate(inputDate, 1)
    print("Result: %s" % dt)

def test(url):
    client = Client(url)
    for p in client.sd[0].ports:
        for m, args in p[1]:
            if len(args) == 0:
                print(client.service[0][m]())

if __name__ == '__main__':
    # set_log()
    url = 'http://localhost:8000/?wsdl'
    if len(sys.argv) > 1:
        url = sys.argv[1]

    call_service(url)
    # test('http://dati.meteotrentino.it/service.asmx?WSDL')
    client1 = Client("http://127.0.0.1:8181/soap/infoservice?wsdl", username='bob', password='catbob')
    print(client1.service.getInfo("Bob"))

    # client2 = Client("http://127.0.0.1:8181/soap/infoservice?wsdl", username='bob', password='catbob')
    # print(client2.service.getInfo("Test2"))
    # 
    # client3 = Client("http://127.0.0.1:8181/soap/infoservice?wsdl", username='bob', password='catbob')
    # print(client3.service.getInfo("Test3"))