[Tutor] robots question

[Evert Rol]

> As a exercise from this book ( Thinking like a computer scientist ) I have to make this programm on this page(http://openbookproject.net/thinkcs/python/english2e/ch12.html)
> Exercise 11 
> 
> #
> # robots.py
> #
> from gasp import *

Argh!
Is that really in the book? 
Bad book, bad.

You can just "import gasp" and type "gasp.<function>" a few times.

<snip>Lot of code</snip>


> def play_game(robots):
>     begin_graphics(SCREEN_WIDTH, SCREEN_HEIGHT)
>     player = place_player()
>     robot = place_robots(4)
>     junk = [place_robot(GRID_WIDTH/2, GRID_HEIGHT/2, junk="true" )]
>     defeated = False
> 
>     while not defeated:
>         quit =  move_player(player)
>         if quit:
>             break
>         move_robots(robot, player)
>         defeated = check_collisions(robot, player, junk)
> 
>     if defeated:
>         remove_from_screen(player['shape'])
>         for thing in robots + junk:
>             remove_from_screen(thing['shape'])
>         Text("They got you!", (240, 240), size=32)
>         sleep(3)
> 
>     end_graphics()
> 
> 
> 
> if __name__ == '__main__':
>     play_game(2)
> 
> But now Im getting this error message :
> 
> Traceback (most recent call last):
>   File "/root/workspace/test2/src/test.py", line 120, in <module>
>     play_game(2)
>   File "/root/workspace/test2/src/test.py", line 106, in play_game
>     defeated = check_collisions(robot, player, junk)
>   File "/root/workspace/test2/src/test.py", line 73, in check_collisions
>     for thing in robots + junk:
> TypeError: can only concatenate list (not "dict") to list
> 
> I understand that robots is a dict and junk is a list.
> 
> Is that right ?

I think robots is not even a dict, but I may be wrong here.
Check your variable *names* inside play_game, and your use of '2' and '4'. Aren't you mixing up 'robot' and 'robots'?
Have you tried putting print statements inside the code? Also 'print type(<varname>)' can be variable.
Try more debugging when you get an exception.


> And why does the book say that when this message is appearing. 

A quick glance at those webpages doesn't show any place where the book gives this code. This seems to be code you added.


  Evert