diff -r 831be7dc260a Lib/test/test_urllib.py
--- a/Lib/test/test_urllib.py	Sat Feb 23 07:53:56 2013 +0200
+++ b/Lib/test/test_urllib.py	Sat Feb 23 18:50:30 2013 +0100
@@ -964,6 +964,33 @@
         result = urllib.parse.urlencode(given)
         self.assertEqual(expect, result)
 
+    def test_quoting_uri(self):
+        uri = "http://localhost"
+        expect = "http://localhost/"
+        result = urllib.parse.quote_uri(uri)
+        self.assertEqual(expect, result)
+
+        uri = "http://localhost/test.html"
+        expect = "http://localhost/test.html"
+        result = urllib.parse.quote_uri(uri)
+        self.assertEqual(expect, result)
+
+        uri = "http://localhost:8080/åäö.html"
+        expect = "http://localhost:8080/%C3%A5%C3%A4%C3%B6.html"
+        result = urllib.parse.quote_uri(uri)
+        self.assertEqual(expect, result)
+
+        uri = "http://slagvärket.örebro.se:8080/åäö.html"
+        expect = "http://xn--slagvrket-z2a.xn--rebro-iua.se:8080/%C3%A5%C3%A4%C3%B6.html"
+        result = urllib.parse.quote_uri(uri)
+        self.assertEqual(expect, result)
+
+        uri = "http://auth:a@sd@slagvärket.örebro.se:8080/å@äö.html"
+        expect = "http://auth:a@sd@xn--slagvrket-z2a.xn--rebro-iua.se:8080/%C3%A5%40%C3%A4%C3%B6.html"
+        result = urllib.parse.quote_uri(uri)
+        self.assertEqual(expect, result)
+
+
     def test_doseq(self):
         # Test that passing True for 'doseq' parameter works correctly
         given = {'sequence':['1', '2', '3']}
diff -r 831be7dc260a Lib/urllib/parse.py
--- a/Lib/urllib/parse.py	Sat Feb 23 07:53:56 2013 +0200
+++ b/Lib/urllib/parse.py	Sat Feb 23 18:50:30 2013 +0100
@@ -981,3 +981,42 @@
     match = _valueprog.match(attr)
     if match: return match.group(1, 2)
     return attr, None
+
+def quote_uri(uri):
+    if not "://" in uri:
+        raise ValueError("{!r} is not a valid URI".format(uri))
+    proto, rest = uri.split("://",1)
+    # Splitting on / as to allow @ in passwords but dissallows / in passwords.. have to choose one
+    if "/" in rest:
+        rest,path = rest.split("/",1)
+        path = quote(path)
+    else:
+        path = ""
+    auth = ""
+    if "@" in rest:
+        items = rest.split("@")
+        rest = items.pop()
+        auth = "@".join(items)
+        auth += "@" # Add trailing @ so that assemply is smoother
+    if ":" in rest:
+        host,port = rest.split(":",1)
+        port = ":"+port # Add starting : so that assemply is smoother
+    else:
+        host = rest
+        port = ""
+    # Encode the hostname with punycode if needed
+    try:
+        host.encode("ascii")
+    except:
+        newhost = []
+        hostparts = host.split(".")
+        for hostpart in hostparts:
+            try:
+                hostpart.encode("ascii")
+                newhost.append(hostpart)
+            except:
+                newhost.append("xn--"+hostpart.encode("punycode").decode("ascii"))
+        host = ".".join(newhost)
+    quoteduri = "{proto}://{auth}{host}{port}/{path}".format(**vars())
+    return quoteduri
+