Python函數—基礎

# ##函數


import math  # 導入math包


# #空函數
# 定義一個空函數 當未想好內部如何寫的時候 用pass

def empty_fun():
    pass

# #多個返回值得函數


def quadratic(a, b, c):
    for i in [a, b, c]:
        if not isinstance(i, (int, float)):  # 調用isinstance檢查數據類型
            raise TypeError('Wrong type!')
    if b * b - 4 * a * c < 0:
        return '無解'
    else:
        x1 = (-b + math.sqrt(b * b - 4 * a * c)) / (2 * a)
        x2 = (-b - math.sqrt(b * b - 4 * a * c)) / (2 * a)
        return x1, x2


def abs_fun(x):
    if not isinstance(x, (int, float)):
        raise TypeError('The number type is wrong')
    if x >= 0:
        return x
    else:
        return -x


print(abs_fun(9))
print(empty_fun())
print(quadratic(2, 3, 1))
print(quadratic(1, 3, -4))