Generate SVG of regular polygons

polygon.py

#!/usr/bin/env python

import argparse
import math

parser = argparse.ArgumentParser(description="""
Generates a SVG of a regular polygon. By default, a convex polygon is generated,
but the --advance option may be used to generate star polygons instead.
""")
parser.add_argument('points', type=int, metavar='POINTS',
                    help='the number of points')
parser.add_argument('--precision', type=int, default=3, metavar='DIGITS',
                    help='number of significant digits for rounding')
parser.add_argument('--scale', type=int, default=1, metavar='RADIUS',
                    help='the radius of the unit circle')
parser.add_argument('--transpose', action='store_true',
                    help='flip X and Y coordinates (start from the top)')
parser.add_argument('--stroke', type=int, default=0, metavar='WIDTH',
                    help='the width of the stroke (border)')
parser.add_argument('--rounded', action='store_true',
                    help='use rounded corners')
parser.add_argument('--advance', type=int, default=1, metavar='POINTS',
                    help='number of points to advance when drawing each line')
args = parser.parse_args()

def p(n):
    rad = 2 * n / args.points * math.pi
    if (args.transpose):
        rad -= math.pi / 2
    return (round(args.scale * math.cos(rad), args.precision),
            round(args.scale * math.sin(rad), args.precision))

origin = -1 * (args.scale + args.stroke / 2)
size = 2 * args.scale + args.stroke
linejoin = 'round' if args.rounded else 'mitre'

path = "M "
for i in range(0, args.points * args.advance, args.advance):
    path += " {0},{1}".format(*p(i % args.points))
path += " z"

svg = f"""
<svg viewBox="{origin} {origin} {size} {size}">
  <path stroke-width="{args.stroke}" stroke-linejoin="{linejoin}"
        d="{path}"/>
</svg>
""".strip()
print(svg)

Samples: https://codepen.io/okorz001/pen/jOmjJjp