Polynomial.py

from random import randrange 

class Zx:
    def __init__(self, coeffs):
        self.coeffs = coeffs
   
    def coefficient(self, n):
        if (type(n) != type(1)) or n < 0:
            print('Coefficient does not exist!')
        if n >= len(self.coeffs):
            return 0
        else:
            return self.coeffs[n]

    def degree(self):
        return len(self.coeffs)-1
   
    def eval(self, x):
        result = 0
        for i in range(len(self.coeffs)):
            result += self.coeffs[i]*(x**i)
        return result

    def add(self, other):
        length = max(self.degree(),other.degree()) + 1
        result = [0] * length
        for i in range(len(result)):
            result[i] = self.coefficient(i) + other.coefficient(i)
        return Zx(result)

    def multiply_single_term(self, coefficient, degree):
        result = Zx(self.coeffs[:])
        result.coeffs[0:0] = [0]*degree
        for i in range(len(result.coeffs)):
            result.coeffs[i] *= coefficient
        return result
        
    def multiply(self, other):      
        result = Zx([])
        for term in range(other.degree()+1):
            result=result.add(self.multiply_single_term(other.coefficient(term),term))
        return result

    def print_polynomial(self):
        terms = []
        for i in range(len(self.coeffs)):
            if i == 0:
                terms.append(str(self.coeffs[i]))
            elif i == 1:
                terms.append(str(self.coeffs[i])+"x")
            else:
                terms.append(str(self.coeffs[i])+"x^"+str(i))
        terms.reverse() 
        return "+".join(terms) 

    def randompoly(self,d,n):
        self.coeffs = [0]*n
        for j in range(d):
            while True:
                r = randrange(n)
                if not self.coeffs[r]: 
                    break
            self.coeffs[r] = 1-2*randrange(2)
        self.print_polynomial()