17aug12
Well, what follows is a bit cryptic. These are three 
attempts to find the optimal starting point for a turtle
circle rtica based on drawing polygons with input 
poly(<number of iterations>, <side length>, <turning angle>)

This lesson is also good for understanding the differences 
between "import" "import *" and whether the helper in turn
imports the turtle stuff itself or not.

If you're impatient, try this: 
======journal=======
westkill-3:circle gfrancis$ python
Python 2.7 (r27:82508, Jul  3 2010, 20:17:05) 
[GCC 4.0.1 (Apple Inc. build 5493)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from circ import *
>>> poly(4,50,90)
=======end==========
and look at square-circle.png of what you should see.
Test your comprehension: how was morepolys.png made?
The polycircle.py illustrates a theorem, what is it?
Here is the code for it
>>> poly(4,124,90)  = square
>>> poly(8,62,45)   = octagon
>>> poly(16,31,22)  = 16-gon
>>> poly(32,15,11)  = 32-gon
Hint: What is constant from one approximation to of a 
circle to the next?




6sep11
if circ.py does an "from turtle import *"
and >>>import circ 
then
>>> dir() adds "circ", while dir(circ) shows all of dir(turtle) as well.
>>> circ.forward(100)    is actually forward(100) 
On the other hand >>> circ.poly(4,120,90)   works

Next, what happens if circl.py does an "import turtle"?
Then, you have to >>> circl.turtle.forward(100)
Now >>> circ.poly(4,120,90)  has no idea what fd means. 

Suppose crcl.py contains NO imports, just the code that assumes
that fd and rt are in the dictionary. Even though 
>>> from turtle import *
>>> fd(100)
works fine
>>> import crcl
>>> crcl.poly(4,120,90)
does not .... so, the dictionaries are not merged.
And it doesn't help that you 
>>> from crcl import *
>>> poly(90,120,90)
still won't work.

This is illogical.

Further, it seems that in order to use 
>>> turtle.__doc__ 
it has to be 
>>> import turtle 
earlier. 

31aug11
Here is an experiment for learning an imported module 
"on the hoof", as it were. Python offers several tools.

The dir() tool. 
The foo.__doc__   
The inspect.py module.

In particular 
>>> inspect.getargspec(turtle.dot)
ArgSpec(args=['size'], varargs='color', keywords=None, defaults=(None,))



dir()
dir.__doc__
import turtle

pytree.__doc__   gives the """ description (that's double underscores)
dir(pytree)      gives the vocabulary