避免程序因 I/O 错误而退出

Question

我有一个广泛使用shutil.copy2 的Python 脚本。由于我使用它通过网络复制文件，因此经常出现 I/O 错误，从而导致程序执行中止：

Traceback (most recent call last):
  File "run_model.py", line 46, in <module>
    main()
  File "run_model.py", line 41, in main
    tracerconfigfile=OPT.tracerconfig)
  File "ModelRun.py", line 517, in run
    self.copy_data()
  File "ModelRun.py", line 604, in copy_ecmwf_data
    shutil.copy2(remotefilename, localfilename)
  File "/usr/lib64/python2.6/shutil.py", line 99, in copy2
    copyfile(src, dst)
  File "/usr/lib64/python2.6/shutil.py", line 54, in copyfile
    copyfileobj(fsrc, fdst)
  File "/usr/lib64/python2.6/shutil.py", line 27, in copyfileobj
    buf = fsrc.read(length)
IOError: [Errno 5] Input/output error

如何避免程序执行中止并让它重试复制过程？

我正在使用的代码已经通过检查文件大小来检查文件是否实际上已完全复制：

def check_file(file, size=0):
    if not os.path.exists(file):
        return False
    if (size != 0 and os.path.getsize(file) != size):
        return False
    return True

while (check_file(rempdg,self._ndays*130160640) is False):
    shutil.copy2(locpdg, rempdg)

Answer 1

哪个块给出了错误？只需在其周围包裹一个 try/ except 即可：

def check_file(file, size=0):
    try:
        if not os.path.exists(file):
            return False
        if (size != 0 and os.path.getsize(file) != size):
            return False
        return True
    except IOError:
        return False # or True, whatever your default is

while (check_file(rempdg,self._ndays*130160640) is False):
    try:
        shutil.copy2(locpdg, rempdg)
    except IOError:
        pass # ignore the IOError and keep going

Answer 2

你可以用它

try:
    ...
except IOError as err:
    ...

来捕获错误并处理它们

看看这个