HTTP Error 401: Unauthorized using urllib.request.urlopen

I'm using urllib.request in python to try and download some build information from Teamcity. This request used to work without username and password, however a recent security change means I must use a username and password. So I have changed tried each of the two solutions below:

Attempt 1)

url = 'http://<domain>/httpAuth/app/rest/buildTypes/<buildlabel>/builds/running:false?count=1&start=0'

# create a password manager
password_mgr = urllib.request.HTTPPasswordMgrWithDefaultRealm()

# Add the username and password.
top_level_url = "http://<domain>/httpAuth/app/rest/buildTypes/id:<buildlabel>/builds/running:false?count=1&start=0"
password_mgr.add_password(None, top_level_url, username, password)

handler = urllib.request.HTTPBasicAuthHandler(password_mgr)

# create "opener" (OpenerDirector instance)
opener = urllib.request.build_opener(handler)

# use the opener to fetch a URL
opener.open(url)

Attempt 2

url = 'http://<username>:<password>@<domain>/httpAuth/app/rest/buildTypes/id:buildlabel/builds/running:false?count=1&start=0'
rest_api = urllib.request.urlopen(url)

Both of these return "HTTP Error 401: Unauthorized". However if I was to print 'url' and copy this output into a browser the link works perfectly. But when used through python I get the above error.

I use something very similar in another Perl script and this works perfectly also.

* SOLVED BELOW *