create a DXF file containing a single polygon

simple_dxf_polygon.py

import numpy as np

class DXFPolygon:
    def __init__(self, x, y):
        self.x = x
        self.y = y
    def write(self, filename):
        x = self.x
        y = self.y
        with open(filename, 'wt') as fout:
            fout.write('0\n')
            fout.write('SECTION\n')
            fout.write('2\n')
            fout.write('ENTITIES\n')
            fout.write('0\n')
            fout.write('POLYLINE\n')
            fout.write('70\n')
            fout.write('1\n') # closed polyline
            fout.write('40\n')
            fout.write('0\n') # start width
            fout.write('41\n')
            fout.write('0\n') # end width

            for i in range(x.shape[0]):
                fout.write('0\n')
                fout.write('VERTEX\n')
                fout.write('10\n')
                fout.write(f'{x[i]}\n')
                fout.write('20\n')
                fout.write(f'{y[i]}\n')
            fout.write('0\n')
            fout.write('SEQEND\n')