Python读取XML并修改导出

Foreword

SES的排除编译文件非常蠢，他不能将这个设置继承给其他配置文件，这就导致如果配置文件很多，每次变动需要把每个配置文件重新设置一次，手动的话很容易设置漏了，所以写个脚本来直接处理这个事情

XML

简单说现在有4个主配置，基于他们每个衍生出来2个配置，也就是一共12个配置，目标是每次只要配置这四个主配置，其他配置就能自动同步他们的排除编译文件的配置。

想了想用批处理或者shell实现，有点麻烦，还是XML，光是分析什么的写起来就很复杂，所以干脆用python写了，CI调用

XML DOM基础

DOM将XML以树状的方式进行构建或者展示，所以每个节点都有子节点或者父节点

<collection shelf="New Arrivals">
<m
   ovie title="Enemy Behind">
   <type>War, Thriller</type>
   <format>DVD</format>
   <year>2003</year>
   <rating>PG</rating>
   <stars>10</stars>
   <description>Talk about a US-Japan war</description>
</movie>
</collection>

这里collection就是一个元素或者节点，可以称之为Element或者Node

一个元素内部的称为属性，比如这里的shelf，就是属性Attribute

而movie则是collection的子节点，同理type format year rating...

这里要注意一个问题，python api中 getElementsByTagName是可以获得此节点下所有符合的Tag，无论他是子节点还是孙节点，只要符合都会返回。

python操作xml，可以直接使用内置的库，不需要额外引用。这里使用xml.dom.minidom来实现

提取排除编译配置

下面基本就能把所有具有排除编译的配置和文件、文件夹提取出来

#!/usr/bin/python
# -*- coding: UTF-8 -*-

import xml.dom.minidom
# open xml
DOMTree = xml.dom.minidom.parse(“demo.emProject”)
collection = DOMTree.documentElement
# test attribute
if collection.hasAttribute(“Name”):
print(“find name”)
project = collection.getElementsByTagName(“project”)[0]
folders = project.getElementsByTagName(“folder”)
print(len(folders))
root_dir = folders[0]
print(“root child:” + str(root_dir.childNodes.length))
exclude_nodes = {}
confs = root_dir.getElementsByTagName(‘configuration’)
if len(confs) > 0:
print(len(confs))
# check all configurations
    for conf in confs:
if conf.hasAttribute(“build_exclude_from_build”):
# save config and parent node
            if conf.parentNode in exclude_nodes:
exclude_nodes[conf.parentNode].append(conf)
else:
exclude_nodes[conf.parentNode] = [conf]
        <span class="c1"># show exclude file

            if conf.hasAttribute(“Name”):
name = conf.parentNode.getAttribute(“Name”)
if name == “”:
name = conf.parentNode.getAttribute(“file_name”)
print(name + " exclude from " + conf.getAttribute(“Name”))

深度、广度优先遍历

有可能会需要深度或者广度优先遍历，我也都随便写了个

def dfs(node):
    if node.hasChildNodes:
        for n in node.childNodes:
            # print(n.nodeType)
            # jump text node
            if (n.nodeType == 1):
                if n.getAttribute("Name") != "":
                    print(n.nodeName + " " + n.getAttribute("Name"))
                elif n.getAttribute("file_name") != "":
                    print(n.nodeName + " " + n.getAttribute("file_name"))
            dfs(n)
    else:
        return
    return
def bfs(nodes):
if len(nodes) > 0:
todo = []
for n in nodes:
if (n.nodeType == 1):
# print(n.childNodes)
                if n.getAttribute(“Name”) != “”:
print(n.nodeName + " “ + n.getAttribute(“Name”))
elif n.getAttribute(“file_name”) != ”“:
print(n.nodeName + ” " + n.getAttribute(“file_name”))
if len(n.childNodes) != 0:
for nc in n.childNodes:
todo.append(nc)
bfs(todo)
else:
return
return
dfs(root_dir)
bfs(root_dir.childNodes)

处理替换分支

这里main asdf就是主要分支了，其他的都是顺势而生的分支

need_CI = ["main", "asdf"]
need_Boot = ["main_boot", "asdf_boot"]
ci_branch_map = {
“main”: “main_CI”,
“asdf”: “asdf_boot”,
}
boot_branch_map = {
“main”: “main_boot”,
“asdf”: “asdf_boot”
}
doc = DOMTree
# deal all exclude node
for node in exclude_nodes:
type = 1
name = node.getAttribute(“Name”)
if name == “”:
type = 2
name = node.getAttribute(“file_name”)
<span class="n">branchs</span> <span class="o">=</span> <span class="p">[]</span>
<span class="n">last_conf</span> <span class="o">=</span> <span class="s">""</span>
<span class="k">for</span> <span class="n">conf</span> <span class="ow">in</span> <span class="n">exclude_nodes</span><span class="p">[</span><span class="n">node</span><span class="p">]:</span>
    <span class="n">branch</span> <span class="o">=</span> <span class="n">conf</span><span class="p">.</span><span class="n">getAttribute</span><span class="p">(</span><span class="s">"Name"</span><span class="p">)</span>
    <span class="c1">#print(name + " exclude from " + branch)

        branchs.append(branch)
last_conf = conf
<span class="n">to_add</span> <span class="o">=</span> <span class="p">[]</span>
<span class="k">for</span> <span class="n">branch</span> <span class="ow">in</span> <span class="n">branchs</span><span class="p">:</span>
    <span class="k">if</span> <span class="n">branch</span> <span class="ow">in</span> <span class="n">need_CI</span><span class="p">:</span>
        <span class="n">ci_branch</span> <span class="o">=</span> <span class="n">ci_branch_map</span><span class="p">[</span><span class="n">branch</span><span class="p">]</span>
        <span class="k">if</span> <span class="n">ci_branch</span> <span class="ow">not</span> <span class="ow">in</span> <span class="n">branchs</span><span class="p">:</span>
            <span class="n">to_add</span><span class="p">.</span><span class="n">append</span><span class="p">(</span><span class="n">ci_branch</span><span class="p">)</span>
            <span class="c1">#print("need add CI " + ci_branch)

        if branch in need_Boot:
boot_branch = boot_branch_map[branch]
if boot_branch not in branchs:
to_add.append(boot_branch)
#print("need add boot " + boot_branch)

# get tab
    tab = last_conf.previousSibling
for branch in to_add:
n = doc.createElement(“configuration”)
    <span class="n">at_name</span> <span class="o">=</span> <span class="n">doc</span><span class="p">.</span><span class="n">createAttribute</span><span class="p">(</span><span class="s">"Name"</span><span class="p">)</span>
    <span class="n">at_name</span><span class="p">.</span><span class="n">value</span> <span class="o">=</span> <span class="n">branch</span>
    <span class="n">n</span><span class="p">.</span><span class="n">setAttributeNode</span><span class="p">(</span><span class="n">at_name</span><span class="p">)</span>

    <span class="n">ex</span> <span class="o">=</span> <span class="n">doc</span><span class="p">.</span><span class="n">createAttribute</span><span class="p">(</span><span class="s">"build_exclude_from_build"</span><span class="p">)</span>
    <span class="n">ex</span><span class="p">.</span><span class="n">value</span> <span class="o">=</span> <span class="s">"Yes"</span>
    <span class="n">n</span><span class="p">.</span><span class="n">setAttributeNode</span><span class="p">(</span><span class="n">ex</span><span class="p">)</span>

    <span class="n">new</span> <span class="o">=</span> <span class="n">node</span><span class="p">.</span><span class="n">insertBefore</span><span class="p">(</span><span class="n">n</span><span class="p">,</span> <span class="n">last_conf</span><span class="p">)</span>
	
    <span class="c1"># for /n

        newline = doc.createTextNode(“”)
node.insertBefore(newline, last_conf)
    <span class="c1"># for indent

        new_tab = tab.cloneNode(deep=False)
node.insertBefore(new_tab, last_conf)
f = open(“demo1.emProject”, “w”)
doc.writexml(f)
f.close()

这里可能最后的地方插入节点的地方有点奇怪。

XML作为一种标记性文本，每个换行和每个制表符或者每个空格，在XML中都是作为一个标记的，也就是说他们也是一种节点（Text类型）。前面没理解这个概念，弄了半天发现输出的XML中，新增节点都是连着的，怎么都不会自动换行，而且前面也没有空格。

属性也是，也有这个概念，用来区分换行和不换行

加入Text Node以后就正常了

Summary

还有另外两种方式操作XML，可能比这种更简单一些

Quote

https://docs.python.org/zh-cn/3/library/xml.dom.html#document-objects

https://docs.python.org/zh-cn/3/library/xml.dom.minidom.html

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