在svg中设置默认单位（Python svgwrite）

Question

I'm generating SVG drawings using python's svgwrite. Every time I want to draw something, I find myself doing this ugly awkward thing:

line = drawing.line(start = "%dmm" % start, end = "%dmm" % end)

I wish I could just do:

line = drawing.line(start = start, end = end)

Is there a way to set the default units to 'mm' for the entire svg drawing?

Answer 1

A possible way is to set the viewBox attribute along with the document sizing,

dwg = svgwrite.Drawing('myDrawing.svg', size=('170mm', '130mm'), viewBox=('0 0 170 130'))

dwg.add(dwg.line(start=(30, 30), end=(50,50)))

dwg.save()

produces for me,

<?xml version="1.0" encoding="utf-8" ?>

<svg baseProfile="full" height="130mm" version="1.1" viewBox="0 0 170 130" width="170mm"
xmlns="http://www.w3.org/2000/svg" xmlns:ev="http://www.w3.org/2001/xml-events" xmlns:xlink="http://www.w3.org/1999/xlink"><defs /><line x1="30" x2="50" y1="30" y2="50" />     </svg>

Answer 2

I just found that you can do this:

from svgwrite import cm, mm
dwg = svgwrite.Drawing('my_drawing.svg', height='10cm', width='10cm')
dwg.add(dwg.line((0*cm, 0*cm), (10*cm, 10*cm))
dwg.save()