[Tutor] serious problem with graphics module

[Gregor Lingl]

roberto schrieb:
> hello everyone
>   
Hello Roberto,

First question:

Do you use Python from the command line (terminal) or do you use IDLE?
I ask this, because these two show different behaviour.
> i have a problem with python 3.0 graphics module:
>
> no problem while importing the module
>   
>>>> import turtle
>>>>         
>
> but when i issue any command like:
>   
>>>> t = turtle.pen()
>>>>         
After performing this command you should be able to observe
a blank window with a tiny black arrow - it's the turtle

pen() is a function in the module turtle. It returns a dictionary
of the attributes of the turtle's pen. Have a look at it:

 >>> print(t)
{'pensize': 1, 'resizemode': 'noresize', 'pendown': True, 'fillcolor': 
'black',
'speed': 3, 'shown': True, 'outline': 1, 'tilt': 0.0, 'pencolor': 'black',
'stretchfactor': (1.0, 1.0), 'shearfactor': 0.0}
 >>>

>>>> t = turtle.forward(60)
>>>>         
>
> nothing appears on the screen, only a blank window, with nothing inside;
> may you give me some hint ?
>   
Hmm, in my window the turtle goes 60 pixels to the right and draws a 
black line.
The statement

 >>> t = turtle.forward(60)

doesn't make much sense, though. It calls the forward() function of the
turtle module and names it's return value t. Alas:

 >>> print(t)
None
 >>>

Not really useful.

 >>> turtle.forward(60)

is sufficient.

What happens if you do this?

 >>> from turtle import *
 >>> for i in range(4):
        forward(100)
        left(90)

Regards,
Gregor


>
> OS: win Xp
>
> thank you in advance !
>
>