Kicad scale footprint

scaler.py

#!/usr/bin/python3

from sexpdata import dump,load,Symbol, dumps as ds
import click
import sys

skip = set(("rotate",))
scaled = set(("xy","xyz","at","size","start","end"))
scaled_width = set(("thickness","width"))

def resize(s, scale):
    if isinstance(s[0], Symbol):
        sn = s[0].value()
        if sn in skip:
            return
        if sn in scaled:
            for i in range(1,len(s)):
                if isinstance(s[i],(int,float)):
                    s[i] = round(s[i] * scale, 10)
                    # this avoids nonsense outut like "1.23400000002"
    for m in s:
        if isinstance(m,list):
            resize(m, scale)

@click.command()
@click.option("-s","--scale", type=float,default=1, help="Scaling factor")
@click.option("-S","--scale-width", is_flag=True, help="Affect line widths")
@click.option("-T","--scale-text", is_flag=True, help="Affect text")
@click.option("-i","--in", "_in", type=click.File("r"), default=sys.stdin,
        help="File to read. Defaults to stdin")
@click.option("-o","--out", "_out", type=click.File("w"), default=sys.stdout,
        help="File to write. Defaults to stdout")
def main(scale,scale_width,scale_text, _in,_out):
    """
    Rescale a KiCAD footprint.
    """
    global scaled

    if not scale_text:
        skip.add("font")
    if scale_width:
        scaled |= scaled_width
    s=load(_in)
    resize(s,scale)
    dump(s,_out)

if __name__ == "__main__":
    main()