python - 发生错误时自动重启程序

Question

程序是这样的：</p>

HEADER CODE
urllib2.initialization()
try:
    while True:
        urllib2.read(somebytes)
        urllib2.read(somebytes)
        urllib2.read(somebytes)
        ...
except Exception, e:
    print e
FOOTER CODE

我的问题是当错误发生（超时、对等连接重置等）时，如何从 urllib2.initialization() 而不是现有的主程序重新启动并再次从 HEADER CODE 重新启动？</p>

Answer 1

您可以将代码包装在“未完成”循环中：

#!/usr/bin/env python

HEADER CODE
done=False
while not done:
    try:
        urllib2.initialization()
        while True:
            # I assume you have code to break out of this loop
            urllib2.read(somebytes)
            urllib2.read(somebytes)
            urllib2.read(somebytes)
            ...
    except Exception, e:    # Try to be more specific about the execeptions 
                            # you wish to catch here
        print e
    else:
    # This block is only executed if the try-block executes without
    # raising an exception
        done=True
FOOTER CODE

Answer 2

将它包装在另一个循环中怎么样？

HEADER CODE
restart = True
while restart == True:
   urllib2.initialization()
   try:
       while True:
           restart = False
           urllib2.read(somebytes)
           urllib2.read(somebytes)
           urllib2.read(somebytes)
           ...
   except Exception, e:
       restart = True
       print e
FOOTER CODE

Answer 3

具有尝试限制的简单方法

HEADER CODE
attempts = 5
for attempt in xrange(attempts):
    urllib2.initialization()
    try:
        while True:
            urllib2.read(somebytes)
            urllib2.read(somebytes)
            urllib2.read(somebytes)
            ...
    except Exception, e:
        print e
    else:
        break
FOOTER CODE