[web2py] How to best create unique strings in python...

[Jason Brower]

I want to make a unique set of chars that people can't just figure out 
what they are for.  The reason for this is to create unique barcodes for 
ticket validation when entiring a conference using my software.  This 
unique letter numb combo would be in a 2d barcode and it entered using a 
restful interface.
I am hoping ticket validation would be with an 8 digit string and 
nametags would use something similar for their individual identification 
with a 4 digit string. Both will be turned into datamatrix codes that 
will be appended to web addresses.  For example, http://iid.me/A123a567 
or http://iid.me/9F4d one would be for validating the ticket, the other 
would be for various perposed depending on who uses it.
Best Regards,
Jason Brower