how to get the coefficients out of the polynomal e

问题:

At the input I get a polynomial as a string, I want to get its coefficients in variables, but i have no idea gow do this. example:7x^4+3x^3-6x^2+x-8.Maximum degree is not known, coefficients are integers. I will be very grateful for any help.

回答1:

Split by plus and minus (e.g. with re.split), preserving the signs in the results. Then for each substring, split by "x" to get the leading coefficient (+1 and -1 are special cases), and take note of missing powers of x (i.e. coefficient 0).