Slicing URL with Python

Question

I am working with a huge list of URL\'s. Just a quick question I have trying to slice a part of the URL out, see below:

http://www.domainname.com/page?CONTEN         


        

Answer 1

import re
url = 'http://www.domainname.com/page?CONTENT_ITEM_ID=1234&param2&param3'
m = re.search('(.*?)&', url)
print m.group(1)

Answer 2

I figured it out below is what I needed to do:

url = "http://www.domainname.com/page?CONTENT_ITEM_ID=1234&param2&param3"
url = url[: url.find("&")]
print url
'http://www.domainname.com/page?CONTENT_ITEM_ID=1234'

Answer 3

This method isn't dependent on the position of the parameter within the url string. This could be refined, I'm sure, but it gets the point across.

url = 'http://www.domainname.com/page?CONTENT_ITEM_ID=1234&param2&param3'
parts = url.split('?')
id = dict(i.split('=') for i in parts[1].split('&'))['CONTENT_ITEM_ID']
new_url = parts[0] + '?CONTENT_ITEM_ID=' + id

Answer 4

Another option would be to use the split function, with & as a parameter. That way, you'd extract both the base url and both parameters.

   url.split("&") 

returns a list with

  ['http://www.domainname.com/page?CONTENT_ITEM_ID=1234', 'param2', 'param3']

Answer 5

The quick and dirty solution is this:

>>> "http://something.com/page?CONTENT_ITEM_ID=1234&param3".split("&")[0]
'http://something.com/page?CONTENT_ITEM_ID=1234'

Answer 6

Parsin URL is never as simple I it seems to be, that's why there are the urlparse and urllib modules.

E.G :

import urllib
url ="http://www.domainname.com/page?CONTENT_ITEM_ID=1234&param2&param3"
query = urllib.splitquery(url)
result = "?".join((query[0], query[1].split("&")[0]))
print result
'http://www.domainname.com/page?CONTENT_ITEM_ID=1234'

This is still not 100 % reliable, but much more than splitting it yourself because there are a lot of valid url format that you and me don't know and discover one day in error logs.