Urllib.encode() - How does it Treat a List?

[=?ISO-8859-1?Q?Gregory_Pi=F1ero?=]

Hi Wise Python Folk,

Here's my code:

p={'type':'bar','title':'Gregs Chart 1','values':[1,2,3],'labels':[1,2,3]}
urllib.urlencode(p)

'values=%5B1%2C+2%2C+3%5D&labels=%5B1%2C+2%2C+3%5D&type=bar&title=Gregs+Chart+1'

Now I just can't figure out what it's giving me for say values? What
is that stuff? What I want is to create a url and pass it a list of
values, ie so that in the script accepting these parameters I can do:

form = cgi.FieldStorage()
values=form.getlist('value')

and values will equal a list with 1,2, 3 or at least '1', '2', '3'

Much thanks in advance!