错误处理问题，似乎无法识别错误

Question

您好问题是，当我尝试在python中运行try expect块时，它似乎没有捕获我的错误。

代码捕获错误，但它没有捕获我设置的错误，我已经尝试if else语句来捕获错误，现在尝试捕获但似乎它只是没有被传递到这些块。

import sys

INVALID_NUM_ARGS_ERROR = "At least two arguments not provided"
INVALID_NUM_ERROR = "Invalid number provided"

def your_main_program(args):
    # Call your methods from here, using the
    # relevant items in args

    num1 = int(sys.argv[1])
    num2 = int(sys.argv[2])

    try:
        if len(sys.argv) == 3:
            multiply(num1, num2)

        elif len(sys.argv) == 4:
            if(num1 or num2 == 0):
                raise_string(num1, num2)

            formula = ''
            formula += (str(num1) + ' * ') * (num2 - 1)
            formula += str(num1)
            print(formula)
            raise_string(num1, num2)

    except ValueError:
        print(INVALID_NUM_ERROR)

我期待[Invalid number provided]的输出，但实际输出结果是[Traceback (most recent call last):]

提高字符串代码

def raise_string(num1, num2):
    "Prints our the two numbers to the power of itself"
    answer = num1**num2
    print(answer)
    return answer

追溯*

Traceback (most recent call last):
  File "script1.py", line 50, in <module>
    your_main_program(sys.argv)
  File "script1.py", line 15, in your_main_program
    num2 = int(sys.argv[2])
ValueError: invalid literal for int() with base 10: 'a'calls

Answer 1

您的代码可能如下所示：

import sys

INVALID_NUM_ARGS_ERROR = "At least two arguments not provided"
INVALID_NUM_ERROR = "Invalid number provided"


def your_main_program(args):
    # Call your methods from here, using the
    # relevant items in args

    try:
        num1 = int(args[1])
        num2 = int(args[2])
    except ValueError:
        print(INVALID_NUM_ERROR)

    length = len(args)
    if length == 3:
        multiply(num1, num2)
    elif length == 4:
        if num1 == 0 or num2 == 0:
            raise_string(num1, num2)
        else:
            formula = " * ".join([str(num1)] * num2)
            print(formula)
            raise_string(num1, num2)


def multiply(n1, n2):
    print(f"{n1} * {n2} = {n1*n2}")


def raise_string(n1, n2):
    print(f"{n1} ** {n2} = {n1**n2}")


if __name__ == "__main__":
    your_main_program(sys.argv)