发生错误时自动重启程序

Question

这个程序是这样的：

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

我想问的是，当出现错误（比如超时、连接被重置等）时，怎么能从urllib2.initialization()这个地方重新开始，而不是从整个主程序重新启动，重新执行头部代码呢？

Answer 1

那我们可以把它放在另一个循环里试试？

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 2

你可以把你的代码放在一个“只要没完成就一直循环”的结构里：

#!/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
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Answer 3

简单的方法，带有尝试次数限制

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