A 3d drawer

iso.py

from turtle import Turtle
from sys import exit

class Point:
    scale = 25
    def __init__(self, x, y, z):
        self.x, self.y, self.z, self._x, self._y, self._z = x, y, z, x*Point.scale, y*Point.scale, z*Point.scale

class Drawer(Turtle):
    def go_home(self):
        self.pu()
        self.home()
        self.pd()

    def go_to_point(self, p):
        self.home()
        self.seth(180)   # x direction
        self.fd(p._x)
        self.seth(45)    # y direction
        self.fd(p._y)
        self.seth(90)    # z direction
        self.fd(p._z)

    def draw_line(self, p1, p2):
        self.pu()
        self.go_to_point(p2)
        position = self.pos()
        self.go_to_point(p1)
        self.pd()
        self.goto(position)

    def draw_shape(self, *l):
        for _x in range(len(l)):
            x = _x - 1
            self.draw_line(l[x], l[x + 1])

def get_fn(t, i):
    if i == 'pu':
        return t.pu
    elif i == 'pd':
        return t.pd
    elif i == 'gp':
        return t.go_to_point
    elif i == 'dl':
        return t.draw_line
    elif i == 'ds':
        return t.draw_shape
    elif i == 'ex':
        return exit
    elif i == 'cl':
        return t.reset
    else:
        return (lambda *a: print('?'))

def run(t, i):
    if len(i) == 2:
        get_fn(t, i[:2])()
    else:
        get_fn(t, i[:2])(*[Point(*[float(y.strip()) for y in x.split(',')]) for x in i[2:].split(';')])

def run_lines(s):
  t = Drawer()
  t.speed(0)               # Speed adjustment
  for x in s.split('\n'):
    if x.strip():
      run(t, x.strip())
  t.go_home()

def shell():
    t = Drawer()
    while True:
        i = input('  > ')
        run(t, i)

# shell()

def prob21():
    run_lines("""
    ds0,0,0;3,0,0;3,0,3
    ds0,2,0;3,2,0;3,2,3
    dl3,0,0;3,2,0
    ds0,0,0;0,1,3;0,2,0
    ds3,0,3;0,1,3;3,2,3
    """)

def prob23():
  run_lines("""
ds0,0,0;3,0,0;3,0,2;2,0,2;2,0,1;0,0,1
ds0,2,0;3,2,0;3,2,2;0,2,2
dl0,0,0;0,2,0
dl3,0,0;3,2,0
dl3,0,2;3,2,2
dl0,0,1;0,2,2
dl2,0,1;0,2,2
dl2,0,2;0,2,2
""")

prob23()

This is in draft form

Added some complex shapes.

Now, it's minimized. For the big, actual version with the shell and everything, just look at the previous commit.

To run a sample model, just uncomment one of bottom two lines. These were given to me as an assignment in class to draw.