update source URL and convert to python3

Author: DrDaveD

print_osg_repos

@@ -1,7 +1,7 @@
-#!/usr/bin/python
+#!/usr/bin/python3
 
-import urllib2
-import libxml2
+import urllib.request
+import lxml.etree
 import sys
 
 printurls = False
@@ -10,13 +10,12 @@ if (len(sys.argv) == 2) and (sys.argv[1] == '-u'):
 elif len(sys.argv) != 1:
     sys.exit("Usage: print_osg_repos [-u]")
 
-response = urllib2.urlopen("http://myosg.grid.iu.edu/vosummary/xml?summary_attrs_showoasis=on&all_vos=on&active=on&active_value=1&sort_key=name")
-xml = response.read()
-doc = libxml2.parseDoc(xml)
+response = urllib.request.urlopen("http://my.opensciencegrid.org/vosummary/xml?summary_attrs_showoasis=on&all_vos=on&active=on&active_value=1&sort_key=name")
+doc = lxml.etree.XML(response.read())
 
 repos = []
-for urlfield in doc.xpathEval("//VO/OASIS/OASISRepoURLs/URL"):
-    url = urlfield.content
+for urlfield in doc.xpath("//VO/OASIS/OASISRepoURLs/URL"):
+    url = urlfield.text
     if url[-1] == '/':
       # remove a trailing slash
       url = url[:-1]
@@ -27,4 +26,4 @@ for urlfield in doc.xpathEval("//VO/OASIS/OASISRepoURLs/URL"):
 
 repos.sort()
 for repo in repos:
-    print repo
+    print (repo)