Create a turtle drawing from .txt file

[deanhystad]

I looked at your initial post and at your sample code and decided the file looks something like this:

red, 15, 200
blue, 150, 200
green, 300, 200
orange, 150, 200
black, 300, 200
red, 150, 200
blue, 300, 200
green, 150, 200

Each line in the file resulting in a turtle drawing a line. I changed some of the colors so it was easier for me to tell which line in the file matches which line in the drawing.

I wrote the simples program to draw the image. It draws a four pointed star.

import turtle

t = turtle.Turtle()

with open('test.txt') as file:
    for line in file:
        color, angle, x = line.split(',')
        t.pencolor(color.strip())
        t.right(int(angle))
        t.forward(int(x))

What I think you are asking for is some way to make this program a bit more robust. My program crashes if there are less that three values in a line.

Error:
Traceback (most recent call last):
  File "...", line 7, in <module>
    color, angle, x = line.split(',')
ValueError: not enough values to unpack (expected 3, got 2)

It also crashes if the angle or distance are not integers.

Error:
Traceback (most recent call last):
  File "...", line 10, in <module>
    t.forward(int(x))
ValueError: invalid literal for int() with base 10: ' 200.1\n'

And it crashes if the file contains a color name that isn't known to Turtle.

Error:
Traceback (most recent call last):
  File "...", line 8, in <module>
    t.pencolor(color.strip())
  File "C:\Program Files\Python38\lib\turtle.py", line 2252, in pencolor
    color = self._colorstr(args)
  File "C:\Program Files\Python38\lib\turtle.py", line 2696, in _colorstr
    return self.screen._colorstr(args)
  File "C:\Program Files\Python38\lib\turtle.py", line 1158, in _colorstr
    raise TurtleGraphicsError("bad color string: %s" % str(color))
turtle.TurtleGraphicsError: bad color string: hubbabubble

I am beginning to understand that your job is to handle these errors and maybe do something a little more graceful. You could attack that problem by verifying the strings before using them as colors or numbers, or you could us try/except to catch the errors when they occur.

Sorry about the cartesian/polar misdirection. That was heading off in a completely wrong direction.