Python将YAML“转换”为XML

1. Background

We have a application that depends on several XML configuration files. The XML files define things like connection settings, polling frequencies, multiple user accounts (using XSD nested types/sequences) etc.

我们有一个依赖于几个XML配置文件的应用程序。 XML文件定义诸如连接设置,轮询频率,多个用户帐户(使用XSD嵌套类型/序列)等内容。

I have the XSD schema for these XML files. Small excerpt below:

我有这些XML文件的XSD架构。摘录如下:

<?xml version="1.0" encoding="ISO-8859-1"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="FooExch"  type="CConfigFooType"/>

<xs:complexType name="CConfigFooType">
  <xs:sequence>
    <xs:element name="_appID" type="xs:string"/>
    ...
    <xs:element name="_logins" type="FooLoginsType" maxOccurs="unbounded"/>
    <xs:element name="_passwords" type="FooPasswordType" maxOccurs="unbounded"/>
    ...
  </xs:sequence>
</xs:complexType>

<xs:complexType name="FooLoginsType">
  <xs:sequence>
    <xs:element name="_name" type="xs:string"/>
    <xs:element name="_adapterID" type="xs:int"/>
    <xs:element name="_FooLogins" type="FooAccountType" maxOccurs="unbounded"/>
  </xs:sequence>
</xs:complexType>

<xs:complexType name="FooAccountType">
  <xs:sequence>
    <xs:element name="_FooAccount" type="xs:string"/>
    <xs:element name="_mktFeed" type="xs:int"/>
  </xs:sequence>
</xs:complexType>

<xs:complexType name="FooPasswordType">
  <xs:sequence>
    <xs:element name="_name" type="xs:string"/>
    <xs:element name="_password" type="xs:string"/>
  </xs:sequence>
</xs:complexType>

</xs:schema>

2. Objective

Our aim is to make it easier for users to tweak or add to settings.

我们的目标是让用户更容易调整或添加设置。

I'd like to offer a script that took a YAML file, and based on the XSD outputted a XML configuration (with default fallbacks for missing values, perhaps in a default.yaml file.).

我想提供一个带有YAML文件的脚本,并根据XSD输出XML配置(缺省值的缺省回退,可能在default.yaml文件中。)。

We'd also need the ability to "append" a YAML to the XML - as in, a user could have a YAML which just defines their user account, and we'd import this to the existing list of user accounts in an existing XML file.

我们还需要能够将YAML“附加”到XML中 - 例如,用户可以拥有一个仅定义其用户帐户的YAML,我们将其导入到现有XML中的现有用户帐户列表中文件。

3. Approach

So far I'm using GenerateDS (http://www.rexx.com/~dkuhlman/generateDS.html) to generate a Python wrapper from the XSD.

到目前为止,我正在使用GenerateDS(http://www.rexx.com/~dkuhlman/generateDS.html)从XSD生成Python包装器。

Using that, I can create a Python object representing the XML schema, then export them to XML.

使用它,我可以创建一个表示XML模式的Python对象,然后将它们导出到XML。

The issue now is how do I go from a YAML to the XML?

现在的问题是如何从YAML转向XML?

Ideally, I'd like a generic loop that just ran over each value, and added it to the Python representation.

理想情况下,我想要一个只运行每个值的泛型循环,并将其添加到Python表示中。

My initial thought was to use getattr(config_wrapper, "yaml_name") = yaml_value and iterate over each value in the YAML, then catch AttributeError for anything that wasn't in the XSD.

我最初的想法是使用getattr(config_wrapper,“yaml_name”)= yaml_value并迭代YAML中的每个值,然后捕获不在XSD中的任何内容的AttributeError。

My first question - are any issues to this approach, or is there perhaps a more Pythonic/cleaner way of doing this? Is there a smarter way of tackling this question?

我的第一个问题 - 这种方法有什么问题,或者是否有更多Pythonic /更清洁的方法呢?是否有更聪明的方法来解决这个问题?

My second question is - with the above part of the XSD, we need to have nested logins, with username/passwords. I know PyYAML offers nested collections, but I'm still not quite sure how this would tie into GenerateDS, or how I could make it generic enough to work reliable.

我的第二个问题是 - 对于XSD的上述部分,我们需要使用用户名/密码进行嵌套登录。我知道PyYAML提供了嵌套集合,但是我仍然不太确定它如何与GenerateDS相关联,或者我如何使它具有通用性以使其可靠工作。

Cheers, Victor

1 个解决方案

#1

I'd avoid the XSD, sounds like a lot of bureaucracy for little gain.

我会避开XSD,听起来像很多官僚机构,收益不大。

Create YAML file with same hierarchy as the XML file.

创建与XML文件具有相同层次结构的YAML文件。

Load file with pyyaml

使用pyyaml加载文件

Loop over result creating the equivalent tree in elementtree.

循环结果在elementtree中创建等效树。

Write tree to XML file

将树写入XML文件

Send XML to system, when it complains, fix YAML and return to step 2.

将XML发送到系统,当它抱怨时,修复YAML并返回到步骤2。

#1