On Wed, Oct 1, 2014 at 5:01 PM, math math <mathemati...@gmail.com> wrote:
> What would be a good starting strategy for writing a program to take the
> derivative of a polynomial expression, such as this below?:
> "x**3 + x**2 + x + 1"
>
> I am a bit confused about my overall strategy. Should one be writing a parser
> class to split the input on operators and then on the double asterisks? Are
> there more clever ways? Or is this something one should solve using
> mathematical formulas instead of parsing the characters?
>
> I just wonder how a seasoned Pythonian would go about a problem like this
> without using a ready-made derivative function from some module.
Well, let's see. Are you planning to use exact Python syntax
everywhere? For instance, will you use asterisks for multiplication
("5*x**3 + 2*x**2 - 5*x + 1")? If so, you could make use of the
ast.parse() module to do some of the work for you. Otherwise, you'll
have to start by writing up a grammar: exactly what is and isn't
allowed? Then write a parser, and see how things go from there.
ChrisA
--
https://mail.python.org/mailman/listinfo/python-list
