how to parse standard algebraic notation

[math math]

Hi,

I am trying to learn Python while solving exercises. 

I want to basically write a program that inputs a polynomial in standard algebraic notation and outputs its derivative.

I know that I need to get the exponent somehow, but I am not sure how to accomplish this in python (3.3)

Do you have any ideas or suggestions? I don't want to use existing modules as this is meant to be a didactic experience.

Regards