Simplify SVGs by applying transform - reduce size

I have quite often some SVGs with structures like this:

<svg:g
  transform="translate(-251.5,36.5)"
  id="g12578"
  style="fill:#ffff00;fill-opacity:1">
  <svg:rect
width="12"
height="12"
x="288"
y="35.999958"
id="rect12580"
style="fill:#ffff00;fill-opacity:1;stroke:#000000;stroke-width:1" />
</svg:g>

I would like to apply translate directly to the coordinates and delete the tranform-attribute:

<svg:g
  id="g12578"
  style="fill:#ffff00;fill-opacity:1">
  <svg:rect
width="12"
height="12"
x="36.5"
y="69.499958"
id="rect12580"
style="fill:#ffff00;fill-opacity:1;stroke:#000000;stroke-width:1" />
</svg:g>

Do you know a script / program for simplifying SVGs? Or a python-snipplet for parsing SVG's?

This script works for my special case, but I would like one which works allways:

#http://epydoc.sourceforge.net/stdlib/xml.dom.minidom.Element-class.html
from xml.dom.minidom import parse, parseString
import re

f = open('/home/moose/mathe/svg/Solitaire-Board.svg', 'r')

xmldoc = parse(f)

p = re.compile('translate\(([-\d.]+),([-\d.]+)\)', re.IGNORECASE)

for node in xmldoc.getElementsByTagName('svg:g'):
  trans开发者_如何学JAVAform_dict = node.attributes["transform"]
  m = p.match(transform_dict.value)
  if m:
    x = float(m.group(1))
    y = float(m.group(2))
  child_rectangles = node.getElementsByTagName('svg:rect') 
  for rectangle in child_rectangles:
    x_dict = rectangle.attributes["x"]
    y_dict = rectangle.attributes["y"]
    new_x = float(x_dict.value) + x
    new_y = float(y_dict.value) + y
    rectangle.setAttribute('x', str(new_x))
    rectangle.setAttribute('y', str(new_y))
  node.removeAttribute('transform')

print xmldoc.toxml()

I think the size of the svg could be reduced quite heavily without loss of quality, if the transform-attribute could be removed. If the tool would be able to reduce coordinate precision, delete unnecessary regions, group and style wisely it would be great.

I'd recommend using lxml. It's extremely fast and has a lot of nice features. You can parse your example if you properly declare the svg namespace prefix. You can do that pretty easily:

>>> svg = '<svg xmlns:svg="http://www.w3.org/2000/svg">' + example_svg + '</svg>'

Now you can parse it with lxml.etree (or xml.etree.ElementTree):

>>> doc = etree.fromstring(svg)

If you use lxml you can take advantage of XPath:

>>> ns = {'svg': 'http://www.w3.org/2000/svg'}

>>> doc.xpath('//svg:g/@transform', namespaces=ns)
<<< ['translate(-251.5,36.5)']

You might want to have a look at scour:

Scour aims to reduce the size of SVG files as much as possible, while retaining the original rendering of the files. It does not do so flawlessly for all files, therefore users are encouraged not to overwrite their original files.

Optimizations performed by Scour on SVG files include: removing empty elements, removing metadata elements, removing unused id= attribute values, removing unrenderable elements, trimming coordinates to a certain number of significant places, and removing vector editor metadata.

1) it can be parsed and edited with regular expression. you can easily get the translate values, and the x,y's.
2) if you checked the minidom, and sure that your only problem is with the ':', so just replace the ':', edit what you need, and then re-replace it to ':'.
3) you can use this question: Is there any scripting SVG editor? to learn how to parse better this XML format.