create a function to construct a finite field in python

main.py
class FieldElement:
    def __init__(self, num, prime):
        if num >= prime or num < 0:
            error = 'Num {} not in field range 0 to {}'.format(num, prime-1)
            raise ValueError(error)

        self.num = num
        self.prime = prime

    def __repr__(self):
        return 'FieldElement_{}({})'.format(self.prime, self.num)

    def __eq__(self, other):
        if other is None:
            return False
        return self.num == other.num and self.prime == other.prime

    def __ne__(self, other):
        if other is None:
            return False
        return not (self == other)

    def __add__(self, other):
        if self.prime != other.prime:
            raise TypeError('Cannot add two numbers in different Fields')
        num = (self.num + other.num) % self.prime
        return self.__class__(num, self.prime)

    def __sub__(self, other):
        if self.prime != other.prime:
            raise TypeError('Cannot subtract two numbers in different Fields')
        num = (self.num - other.num) % self.prime
        return self.__class__(num, self.prime)

    def __mul__(self, other):
        if self.prime != other.prime:
            raise TypeError('Cannot multiply two numbers in different Fields')
        num = (self.num * other.num) % self.prime
        return self.__class__(num, self.prime)

    def __rmul__(self, coeff):
        num = (self.num * coeff) % self.prime
        return self.__class__(num=num, prime=self.prime)

    def __pow__(self, n):
        n = n % (self.prime - 1)
        num = pow(self.num, n, self.prime)
        return self.__class__(num=num, prime=self.prime)

    def __truediv__(self, other):
        if self.prime != other.prime:
            raise TypeError('Cannot divide two numbers in different Fields')
        num = (self.num * pow(other.num, self.prime - 2, self.prime)) % self.prime
        return self.__class__(num=num, prime=self.prime)

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main.py
a = FieldElement(7, 13)
print(a)
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3 lines