从XML在Python中以列表样式（表格）打印数据

Question

我想把我的服务器按照列表的方式打印出来。像这样：

Machine  | Group               | IP            | Services
- Alpha  | Public Server Group | 192.168.1.251 | JBoss, Tomcat
- Public | Public Server Group | 192.168.1.253 | JBoss, Tomcat

我的XML内容是：

<?xml version="1.0" ?>
<AllConfigurations>

<DeployConfigurations>

    <Servers>

        <Group id="1" name="Public Server Group" username="root" password="mypasswd123" state="">
            <GApp id="1" name="JBoss Servers" type="JBoss" path="/root/Desktop/jboss-as-7.0.2.Final/" state="">
                <Server id="1" name="Alpha" ip="192.168.1.251" path="/root/Desktop/jboss-as-7.0.2.Final/" username="" password="" state="" />
                <Server id="2" name="Public" ip="192.168.1.253" path="/root/Desktop/jboss-as-7.0.2.Final/" username="" password="" state="" />
            </GApp>
            <GApp id="2" name="Tomcat Servers" type="Tomcat" path="/root/Desktop/apache-tomcat-7.0.22/" state="">
                <Server id="1" name="Alpha" ip="192.168.1.251" path="/root/Desktop/apache-tomcat-7.0.22/" username="" password="" state="" />
                <Server id="2" name="Public" ip="192.168.1.253" path="/root/Desktop/apache-tomcat-7.0.22/" username="" password="" state="" />
            </GApp>
        </Group>

    </Servers>

</DeployConfigurations>

</AllConfigurations>

我正在尝试这样做：

from xml.dom.minidom import parse

yXML = parse('/root/Desktop/gb/data/yConfig.xml')

print (' ')
print ('Machine       |       Group       |       IP       |       Services')

for AllConfigurations in yXML.getElementsByTagName('AllConfigurations'):
    for DeployConfigurations in AllConfigurations.getElementsByTagName('DeployConfigurations'):
        for Servers in DeployConfigurations.getElementsByTagName('Servers'):
            for Group in Servers.getElementsByTagName('Group'):
                for GApp in Group.getElementsByTagName('GApp'):
                    for Server in Group.getElementsByTagName('Server'):

                        print Server.getAttribute('name') + ' | ' + Group.getAttribute('name') + ' | ' + Server.getAttribute('ip') + ' | ' + GApp.getAttribute('type')

我的结果是：

Machine  | Group               | IP            | Services
Alpha | Public Server Group | 192.168.1.251 | JBoss
Public | Public Server Group | 192.168.1.253 | JBoss
Alpha | Public Server Group | 192.168.1.251 | JBoss
Public | Public Server Group | 192.168.1.253 | JBoss
Alpha | Public Server Group | 192.168.1.251 | Tomcat
Public | Public Server Group | 192.168.1.253 | Tomcat
Alpha | Public Server Group | 192.168.1.251 | Tomcat
Public | Public Server Group | 192.168.1.253 | Tomcat

我该怎么做呢？

它会为每一种可能性都打印出来。我无法把服务并排对齐，只能为一个IP打印，看起来像个表格。

需要帮助..

Answer 1

我觉得你需要利用Python中的一种叫做格式规范小语言的东西：

data = ('Machine', 'Group', 'IP', 'Services')
# left aligned (default)                                                                                                                  
print '{0:20} | {1:20} | {2:20} | {3:20}'.format(*data)
# rigth aligned (default)                                                                                                                 
print '{0:>20} | {1:>20} | {2:>20} | {3:>20}'.format(*data)
# centered                                                                                                                                
print '{0:^20} | {1:^20} | {2:^20} | {3:^20}'.format(*data)

上面脚本的输出结果是：

Machine              | Group                | IP                   | Services
             Machine |                Group |                   IP |             Services
      Machine        |        Group         |          IP          |       Services

Answer 2

首先，你不能直接打印出这些行，而是要把数据存储在一个列表里（叫做 servers），每条数据用元组的形式保存。为了按机器、组或IP来分组服务，你可以使用 itertools 里的 groupby 函数，并把前三个字段作为关键元组来指定。（在这之前，列表需要先排序，这样 groupby 才能找到所有重复的项。）groupby 会返回一个关键元组（3个元素的元组）和一个生成器，用来获取对应的其他行；在这里，我们关注的是第四个值（服务）的唯一值，所以我们把这些值转换成一个 set（集合），并用空格把它们连接起来。

关于对齐表格的问题，可以通过使用 string 里的 ljust 函数（左对齐）来解决。我还写了一个单独的函数，用来通用化表头和数据行的渲染。

下面是代码：

from itertools import groupby

servers = []
for AllConfigurations in yXML.getElementsByTagName('AllConfigurations'):
    for DeployConfigurations in AllConfigurations.getElementsByTagName('DeployConfigurations'):
        for Servers in DeployConfigurations.getElementsByTagName('Servers'):
            for Group in Servers.getElementsByTagName('Group'):
                for GApp in Group.getElementsByTagName('GApp'):
                    for Server in Group.getElementsByTagName('Server'):
                        servers.append((Server.getAttribute('name'),
                                Group.getAttribute('name'),
                                Server.getAttribute('ip'),
                                GApp.getAttribute('type')))

def line(machine, group, ip, services):
    return " | ".join([machine.ljust(8), group.ljust(20), ip.ljust(15), services])

print line("Machine", "Group", "IP", "Services")
for server, services in groupby(sorted(servers), lambda server: server[0:3]):
    print line("- " + server[0], server[1], server[2],
            ", ".join(service[3] for service in set(services)))

这段代码会打印出：

Machine  | Group                | IP              | Services
- Alpha  | Public Server Group  | 192.168.1.251   | JBoss, Tomcat
- Public | Public Server Group  | 192.168.1.253   | Tomcat, JBoss