Help: How to capture invalid web page from urllib?

[Richard Jones]

On Monday 15 October 2001 13:56, Paul Lim wrote:
> I am trying to open a web page from command line. If the web page is not
> valid, I hope to capture the exception and print an error message and
> exit.
>
> What I currently have is as below, but I am certain I used the wrong
> class because I did not managed to capture the exception (if any) raise.
>
> Could someone teach me how to test the validity of a web page, ie
> whether does it exist, can it be open?
>
> # If web page is entered, check whether it is a valid web page
>  try:
>     inf = urllib.URLopener.http_error_default(sys.argv[1])
>  except IOError:
>     print "Invalid webpage!"
>     print "Usage : ./webmap.py http://server-name/path-to-document"
>     sys.exit()

The following should be enough:

>>> try:
...  urllib.urlopen('http://com.foo')
... except IOError:
...  print "Page doesn't exist"
... 
Page doesn't exist
>>> 



     Richard