EnlargePads v0.1a

#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# EnlargePads v0.1a
# A very simple program for enlarging pads in svg as output from Fritzing
# At the moment, not much care is taken to not break stuff, so please check
# the result yourself before etching.
#
# Copyright (c) 2013 Niels Kjoeller Hansen <niels.k.h@gmail.com>
# This work is free. You can redistribute it and/or modify it under the
# terms of the Do What The Fuck You Want To Public License, Version 2,
# as published by Sam Hocevar. See http://www.wtfpl.net/ for more details.
#

from xml.dom import minidom

# Setting up
filename = "test_print.svg"
drill_hole_diameter_mil = 40 #(40 mil =~ 1mm)
pad_diameter_mil = 75

# Calculating radius and stroke-width (pixels @ 90ppi)
new_sw = (pad_diameter_mil - drill_hole_diameter_mil)*0.09/2
new_r = (pad_diameter_mil*0.09 - new_sw)/2

# Parsing the xml
xmldoc = minidom.parse(filename)

# Iterating through elements of type "circle"
for circle in xmldoc.getElementsByTagName('circle'):
    # Checking if attributes has keys (if they have not, something is wrong)
    if 'r' in circle.attributes.keys() and \
       'stroke-width' in circle.attributes.keys():
        # Only enlarging small circles
        if float(str(circle.attributes['r'].value)) < new_r and \
           float(str(circle.attributes['stroke-width'].value)) < new_sw:
            circle.attributes['r'] = str(new_r)
            circle.attributes['stroke-width'] = str(new_sw)

# Writing to a new file with "_enlargedpads" appended to the filename
new_filename = ".".join(filename.split('.')[:-1]) + \
                '_enlargedpads.' + filename.split('.')[-1]
a = open(new_filename,'w')
a.write(xmldoc.toxml())
a.close()