如何以我自己的方式处理python生成的错误消息？

Question

对于一些代码如下，

    opts, args = getopt.getopt(sys.argv[1:], "c:", ...
    for o,v in opts:
...
        elif o in ("-c", "--%s" % checkString):
            kCheckOnly = True
            clientTemp = v

如果我不在-c之后给出参数，我会得到如下错误消息。

Traceback (most recent call last):
  File "niFpgaTimingViolationMain.py", line 100, in 
    opts, args = getopt.getopt(sys.argv[1:], "hdc:t:",[helpString, debugString, checkString, twxString])
  File "/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/getopt.py", line 91, in getopt
    opts, args = do_shorts(opts, args[0][1:], shortopts, args[1:])
  File "/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/getopt.py", line 195, in do_shorts
    opt)
getopt.GetoptError: option -c requires argument

有没有办法捕获这个错误，并处理它打印这样的东西？似乎只是在try / except中包装代码不起作用。

ERROR: You forgot to give the file name after -c option

Answer 1

您可以捕获getopt.GetoptError并自行检查'opt'和'msg'属性：

try:
    opts, args = getopt.getopt(sys.argv[1:], "c:", ...
except getopt.GetoptError, e:
    if e.opt == 'c' and 'requires argument' in e.msg:
        print >>sys.stderr, 'ERROR: You forgot to give the file name after -c option'
        sys.exit(-1)

Answer 2

正确答案是使用OptionParser模块而不是尝试“自己动手”。