I'm almost sure that there's no way for a turtle to know anything about the background. That's an unfortunate limitation!
As for putting a limit on a turtle's travel, you need to write an appropriate conditional. For example, if you want your turtle to stay within a 200x200 square centered around the origin and stop if it gets out, do something roughly like: while(math.abs(t.xcor()) < 100 and math.abs(t.ycor()) < 100): move turtle Of course, you could instead use if statements and simulate bouncing (if my turtle's x coordinate is beyond my bounding box, subtract from its x coordinate). Best, Hélène. Computer Science Teacher Garfield High School http://garfieldcs.com On Sun, Jan 24, 2010 at 7:29 AM, Brian Blais <bbl...@bryant.edu> wrote: > Hello, > I am trying to think of things to do with the turtle module with my > students, and I have some ideas where I am not sure whether the turtle > module can do it. > 1) is there a way to determine the current screen pixel color? I am > thinking about having the turtle go forward until it reaches an object, say > a red circle. I can probably do this by making circle objects (drawn with > turtles themselves) which know their own position, and check against this > info. But I thought it might be useful also for the turtle to know. > 2) is there a way to put a limit on the extent the turtle can travel? it > seems I can keep moving off of the screen. Is there a way to make it so > that a forward(50) command, at the edge, either raises an exception (at the > wall) or simply doesn't move the turtle because of the limit? > > thanks! > > bb > > -- > Brian Blais > bbl...@bryant.edu > http://web.bryant.edu/~bblais > http://bblais.blogspot.com/ > > > > _______________________________________________ > Edu-sig mailing list > edu-...@python.org > http://mail.python.org/mailman/listinfo/edu-sig > > -- http://mail.python.org/mailman/listinfo/python-list
