我不明白为什么。它会引发一个错误'int'对象没有属性'v'，但我想访问self.v.当我只打印self时，它会打印一些数字。我不明白发生了什么。这是我的代码。

class Candidate:
    def __init__(self,val,pscore,nscore):
        self.v = val
        self.p = pscore
        self.n = nscore

    def __str__(self):
        return f"{self.v} ({self.p},{self.n})"

    def check_plus_pos(self, guessval):
        count = 0
        b = self.v
        a = str(b)
        guessval = str(guessval)
        for i in range(0,len(a)):
            if a[i] == guessval[i]:
                count += 1
        return count

    def check_neg_pos(self, guessval):
        count = 0
        b = self.v
        a = str(b)

        guessval = str(guessval)
        for i in range(0,len(a)):
            for j in range(0,len(guessval)):
                if a[i] == guessval[j] and a[i] != guessval[i]:
                    count += 1
        return count

    def consistent(self, guess):
        if Candidate.check_plus_pos(self,guess.v) == guess.p and Candidate.check_neg_pos(self,guess.v) == guess.n:
            return True
        else:
            return False

问题发生在b == self.v，我想将self.v值赋给一个变量。