代码尝试更改为 int 时输入为字符串时出错，try/except 不会捕获它答案

【问题标题】：Code Gives an error when input is a string when trying to change to an int, try/except does not catch it代码尝试更改为 int 时输入为字符串时出错，try/except 不会捕获它
【发布时间】：2021-11-28 16:38:37
【问题描述】：

我正在编写一段 python 代码，允许您切换默认打印机。它将wmic printer list brief 的数据输出到一个 .json 文件中，并列出那些带有分配编号的打印机。如果输入未包含在数字中，则会向用户抛出错误。如果用户输入一个字符而不是数字，则从 string 到 int 的转换失败，我无法获得 try/except 来捕获错误。任何帮助都会很棒！

    def setDefaultPrinter():
    with open('resources/data.json') as json_file:
        data = json.load(json_file)
        loopvalue = 1
        print('\n List of avalible printers: \n')
        printerlist = []
        error = False
        for i in data:
            print(str(loopvalue) + ". " + i)
            loopvalue += 1
            printerlist.append(i)
            #any(printer in x for x in lst)
        try:
            global printer
            printer = int(input("\nWhat printer do you want to use? (Number on the side): "))
        except ValueError:
            print("Please enter a number, not a letter")
            error = True
        except Exception:
            print("Internal Error")
        try:
            if printer == None:
                print("Error")
        except Exception:
            print("ERROR")
            error = True
        if printer <= len(printerlist) and not error:
            printer = int(printer)
            printervalue = printer - 1
            printername = printerlist[printervalue]
            print(printername)
        else:
            if error == False:
                print("Invalid Responce")

【问题讨论】：

标签： python json printing integer wmic

【解决方案1】：

def setDefaultPrinter():
with open('resources/data.json') as json_file:
    data = json.load(json_file)
    loopvalue = 1
    print('\n List of avalible printers: \n')
    printerlist = []
    error = False
    for i in data:
        print(str(loopvalue) + ". " + i)
        loopvalue += 1
        printerlist.append(i)
        #any(printer in x for x in lst)
    printer = input("\nWhat printer do you want to use? (Number on the side): ")
    if not printer.isdigit():
        error = True
        print("\nValue Error: Please Check Your Input")
    if not error and int(printer) <= len(printerlist):
        printer = int(printer)
        printervalue = printer - 1
        printername = printerlist[printervalue]
        print(printername)
    else:
        if error == False:
            print("Invalid Responce")

【讨论】：

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