错误捕获与计数器不工作相结合

Question

我正在制作一个代码，让用户逐行输入 RLE。然后我将输入的数据发送到对其进行解码的函数。在该函数中，我包含了一些基本的错误捕获。

我的错误是，当用户只能输入错误数据时，他们选择的次数（他们选择他们想要输入的行数）。也就是说，如果用户输入了 2 行（共 3 行）正确的 RLE 行，然后输入了错误的行，代码将不会要求再次输入 RLE，但如果他们在第一次或第二次输入时输入了错误的行，它就会起作用。

代码：

if line_amount>2:
            print ("Please enter the compressed data one line at a time")
            while line_amount > counter:
                compressed_data = input('->') #ENTER RLE DATA
                counter+=1
                RLEtoASCII(compressed_data,counter)

RLE转ASCII:

def RLEtoASCII(compressed_data,counter):
    try:
        pairs = [(int(compressed_data[i:i+2]), compressed_data[i+2]) for i in range(0, len(compressed_data), 3)]
        global text
        text = ''.join(n * c for n, c in pairs)
        RLE_Inputs = open("Entered Data.txt", 'a+') #File that lists all the inputs
        #[etc all the file writing]
    except:
        print('THERE WAS A PROBLEM WITH THE VALUES Please re-enter values.\n')

如果我尝试在 except 之后调用 RLEtoASCII，它会创建一个循环。 counter -=1 之后似乎不起作用，除了...

Answer 1

尝试将 while line_amount > counter: 中的 > 更改为 >=。这是因为当您到达第三行时，它正在测试 if 3>3 是否为假，而 3>=3 是否为真。

Answer 2

问题似乎是即使您发现错误，counter 也会递增。我将 counter 更改为全局，以便在出现错误时它不会有效地增加。只需确保将 global counter 置于定义之上即可。让我知道这是否适合你。

if line_amount>2:
            print ("Please enter the compressed data one line at a time")
            while line_amount > counter:
                compressed_data = input('->') #ENTER RLE DATA
                counter+=1
                RLEtoASCII(compressed_data)

RLE转ASCII:

def RLEtoASCII(compressed_data):
    global counter
    try:
        pairs = [(int(compressed_data[i:i+2]), compressed_data[i+2]) for i in range(0, len(compressed_data), 3)]
        global text
        text = ''.join(n * c for n, c in pairs)
        RLE_Inputs = open("Entered Data.txt", 'a+') #File that lists all the inputs
        #[etc all the file writing]
    except:
        print('THERE WAS A PROBLEM WITH THE VALUES Please re-enter values.\n')
        counter-=1

Answer 3

通过将错误处理移出您的函数并移至 if 循环中，我们可以更轻松地控制迭代：

if line_amount>2:
            print ("Please enter the compressed data one line at a time")
            while line_amount > counter:
                compressed_data = input('->') #ENTER RLE DATA
                if compressed_data != '':
                    try:
                        RLEtoASCII(compressed_data)
                        counter+=1
                    except:
                        print('THERE WAS A PROBLEM WITH THE VALUES Please re-enter values.\n')

RLE转ASCII:

def RLEtoASCII(compressed_data):
    pairs = [(int(compressed_data[i:i+2]), compressed_data[i+2]) for i in range(0, len(compressed_data), 3)]
    global text
    text = ''.join(n * c for n, c in pairs)
    RLE_Inputs = open("Entered Data.txt", 'a+') #File that lists all the inputs
    #[etc all the file writing]

错误捕获与计数器不工作相结合

Error trapping combined with a counter not working

python

error-handling

loops

try-except