I'm trying this simple code, but the damn break doesn't work... what is wrong?
while True:
for proxy in proxylist:
try:
h = urllib.urlopen(website, proxies = {'http': proxy}).readlines()
print 'worked %s' % proxy
break
except:
print 'error %s' % proxy
print 'done'
It's supposed to leave the while when the connection work, and go back and try another proxy if it didn't
ok, here is what I'm doing
I'm trying to check a website and if it changed, it has to break out of the whil开发者_如何学Ce to continue to the rest of the script, but when the proxy doesn't connect, I get error from the variable, as it's null, so what I want is this for work as loop to try a proxy, and if it work, continue the script, and the end of the script, go back and try the next proxy, and if the next doesn't work, it will be back to the beginning to try the third proxy, and so on....
I'm trying something like this
while True:
for proxy in proxylist:
try:
h = urllib.urlopen(website, proxies = {'http': proxy})
except:
print 'error'
check_content = h.readlines()
h.close()
if check_before != '' and check_before != check_content:
break
check_before = check_content
print 'everything the same'
print 'changed'
You just break out of for
loop -- not while
loop:
running = True
while running:
for proxy in proxylist:
try:
h = urllib.urlopen(website, proxies = {'http': proxy}).readlines()
print 'worked %s' % proxy
running = False
except:
print 'error %s' % proxy
print 'done'
You can use a custom exception and then catch it:
exit_condition = False
try:
<some code ...>
if exit_conditon is True:
raise UnboundLocalError('My exit condition was met. Leaving try block')
<some code ...>
except UnboundLocalError, e:
print 'Here I got out of try with message %s' % e.message
pass
except Exception, e:
print 'Here is my initial exception'
finally:
print 'Here I do finally only if I want to'
You break out of the for
loop only, so you never leave the while loop and restart iterating over the proxylist
over and over again. Just omit the surrounding while loop, I actually don't understand why you enclosed the code in a while True
in the first place.
break is breaking the innermost loop, which is the for
loop in your case. To break from more than one loop you have few options:
- Introduce a condition
- Create a sub and use
return
but in your case you actually don't need the outer while
loop at all. Just remove it.
精彩评论