Python 错误检查

Question

我正在使用下面的代码。请问我该如何添加错误检查呢？

如果出现任何错误，就把“继续阅读”替换掉。

比如说，如果音量是N\a或者缺失，就用“一个值”来替换。

不要跳过这一行，也不要停止执行。

reader = csv.reader(idata.split("\r\n"))

stocks = []
for line in reader:
    if line == '':
        continue

    stock, price, volume, stime = line
    price = float(price)
    volume = int(volume)

    stocks.append((stock, price, volume, stime))

Answer 1

可以像下面这样做：

def isRecordValid(stock,price,volume,stime):
    #do input validation here, return True if record is fine, False if not.  Optionally raise an Error here and catch it in your loop
    return True

reader = csv.reader(idata.split("\r\n"))

stocks = []
for line in reader:
    if line == '':
        continue

    stock, price, volume, stime = line
    try:
        if isRecordValid(stock,price,volume,stime):
            price = float(price)
            volume = int(volume)
            stocks.append((stock, price, volume, stime))
        except Exception as e:
            print "either print or log and error here, using 'except' means you can continue execution without the exception terminating your current stack frame and being thrown further up"

基本上，你需要定义另一个方法（或者直接在这里写）来检查股票、价格、交易量和时间是否都是你预期的那样。我建议在这里也捕捉任何错误，以防你在把价格和交易量的字符串转换成浮点数或整数时出现问题。