Simple interface to minidom for creating XML files

Mon Sep 27 00:20:56 EDT 2010

Hello,
I want to create some XML files, following a simple template. For that
purpose, I created a simple interface to minidom. This is simple code,
but as I spend a little time for understanding how minidom was
working, I thought that this may be useful for someone (not that
minidom is complex, but even if simplified from the full XML
implementation, it still possesses too many functions for what I
simply wanted to do).
What you have to do is just to import the class doc, and then:
In [258]: xml=doc("toto")
In [259]: xml["part1"]=None
In [260]: xml["part1"]["1.1"]="coucou"
In [261]: xml["part1"]["1.2"]="toto"
In [262]: xml["part1"]["1.2"]["1.2.1"]="a"
In [263]: xml["part1"]["1.2"]["1.2.2"]="b"
In [264]: xml["part2"]="That's all folks!"
In [265]: xml["part1"]["1.2"]["1.2.2"]="really b"
In [266]: xml["part1"]["cdata"]="This is\nMore complex data\n:-p\n"
In [267]: xml.write("test.xml")
is sufficient to obtain the following file:
<?xml version="1.0" ?>
<toto>
 <part1>
 <1.1>
 coucou
 </1.1>
 <1.2>
 toto
 <1.2.1>
 a
 </1.2.1>
 <1.2.2>
 really b
 </1.2.2>
 </1.2>
<![CDATA[This is
More complex data
:-p
]]>
 </part1>
 <part2>
 That's all folks!
 </part2>
</toto>
This piece of code is way too small for being considered as a real
package, but it may help someone. Thus, I am just posting it here so
that it doesn't get lost. Please feel free to use it and extend it as
will (I put a GPL licence in that purpose).
If you have some comments/suggestion about this code, I would also be
happy to discuss about it :).
Raphaël
Here is the code:
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# Copyright 2010 Raphael Plasson, rplasson_at_gmail_dot_com
#
# This program is free software: you can redistribute it and/or
# modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/
>.

from xml.dom.minidom import Document
class node:
 def __init__(self,name,parent,doc):
 '''Add a node called <name> to the document <doc> inside the
node <parent>'''
 self.name=name
 self.parent=parent
 self.doc=doc
 self.element=self.doc.createElement(self.name)
 self.parent.element.appendChild(self.element)
 self.children={}
 def __getitem__(self,key):
 return self.children[key]
 def __setitem__(self,key,val):
 if key=="text":
 self.set_text(val)
 elif key=="cdata":
 self.set_cdata(val)
 else:
 tmp=self.set_node(key)
 if val != None:
 tmp.set_text(val)
 def __repr__(self):
 tmp=self.name+" : "
 for i in self.children:
 tmp += i+", "
 return tmp
 def __newchild(self,child,name):
 self.children[name] = child
 def set_node(self,name):
 '''Add a node <name>.
 If a node with the same name already exists,
 it is simply returned.'''
 if self.children.has_key(name):
 return self.children[name]
 else:
 tmp=node(name,self,self.doc)
 self.__newchild(tmp,name)
 return tmp
 def set_text(self,text):
 '''Add or update the node text <text>'''
 if self.children.has_key("text"):
 self.children["text"].data=text
 else:
 tmp=self.doc.createTextNode(text)
 self.__newchild(tmp,"text")
 self.element.appendChild(tmp)
 def set_cdata(self,cdata):
 '''Add or update the node cdata <cdata>'''
 if self.children.has_key("cdata"):
 self.children["cdata"].data=cdata
 else:
 tmp=self.doc.createCDATASection(cdata)
 self.__newchild(tmp,"cdata")
 self.element.appendChild(tmp)
 self.element.appendChild(self.doc.createTextNode("")) #
dirty hack for adding newline after CDATA in file
 def set_attr(self,attr,val):
 '''Add or set the attribute <attr> to <val>'''
 self.element.setAttribute(attr,val)
 def comment(self,comm):
 '''Add the comment <comm>'''
 self.element.appendChild(self.doc.createComment(comm))
class doc(node):
 def __init__(self,name):
 ''' Create an xml document, with root node <name>'''
 self.name=name
 self.parent=None
 self.doc=Document()
 self.element=self.doc.createElement(self.name)
 self.doc.appendChild(self.element)
 self.children={}
 self.text=""
 def write(self,filename):
 ''' Write the xml document to <filename>'''
 out=file(filename,"w")
 self.doc.writexml(out, newl="\n", addindent=" ")
 out.close()
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