《python语言程序设计》2018版第7章第06题代数：平方根 设计一个名为QuadraticEquation类

类代码部分

class QuadraticEquation:
    def __init__(self, a, b, c):
        self.a = a
        self.b = b
        self.c = c

    def set_a(self, a):
        self.a = a

    def get_a(self):
        return self.a

    def set_b(self, b):
        self.b = b

    def get_b(self):
        return self.b

    def set_c(self, c):
        self.c = c

    def get_c(self):
        return self.c

    def get_discrimination(self):
        return pow(self.b, 2) - (4 * self.a * self.c)

    def get_root1(self):
        root_num1 = pow(QuadraticEquation.get_discrimination(self), 0.5)
        root_num2 = -self.b + root_num1
        return root_num2 / (2 * self.a)

    def get_root2(self):
        root_num1 = pow(QuadraticEquation.get_discrimination(self), 0.5)
        root_num2 = -self.b - root_num1
        return root_num2 / (2 * self.a)

    def get_judge_num(self):
        a_num = QuadraticEquation.get_discrimination(self)
        b_num1 = QuadraticEquation.get_root1(self)
        b_num2 = QuadraticEquation.get_root2(self)

        if a_num == 0:
            return f"The root is {b_num1 or b_num2}"
        elif a_num > 0:
            return "The roots are {:.5f} and {:.5f}".format(b_num1, b_num2)
        else:
            return "The equation has no real roots"

main部分

def main():
    con_method1 = exCode07.QuadraticEquation(1, 3, 1)
    con_method2 = exCode07.QuadraticEquation(1, 2, 1)
    con_method3 = exCode07.QuadraticEquation(1, 2, 3)
    print(f"#1 method result is {con_method1.get_judge_num()}")
    print(f"#2 method result is {con_method2.get_judge_num()}")
    print(f"#3 method result is {con_method3.get_judge_num()}")


main()

顺便这个是4.1题的代码，只不过经过我多次学习用的

04.01 code


def roots(a, b, c):
    con_method = pow(b, 2) - (4 * a * c)

    r1 = (-b + pow(con_method, 0.5)) / (2 * a)
    r2 = (-b - pow(con_method, 0.5)) / (2 * a)
    if con_method == 0:
        print(f"The root is {r1 or r2}")
    elif con_method > 0:
        print("The roots are {:.5f} and {:.5f}".format(r1, r2))
    else:
        print("The equation has no real roots")

roots(1,3,1)
roots(1,2,1)
roots(1,2,3)