HTTP Basic Authentication not working with Python 3 - http-headers

Question

I am trying to access an intranet site with HTTP Basic Authentication enabled.
Here's the code I'm using:
from bs4 import BeautifulSoup
import urllib.request, base64, urllib.error
request = urllib.request.Request(url)
string = '%s:%s' % ('username','password')
base64string = base64.standard_b64encode(string.encode('utf-8'))
request.add_header("Authorization", "Basic %s" % base64string)
try:
u = urllib.request.urlopen(request)
except urllib.error.HTTPError as e:
print(e)
print(e.headers)
soup = BeautifulSoup(u.read(), 'html.parser')
print(soup.prettify())
But it doesn't work and fails with 401 Authorization required. I can't figure out why it's not working.

Answer 1

The solution given here works without any modifications.
from bs4 import BeautifulSoup
import urllib.request
# create a password manager
password_mgr = urllib.request.HTTPPasswordMgrWithDefaultRealm()
# Add the username and password.
# If we knew the realm, we could use it instead of None.
top_level_url = "http://example.com/foo/"
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
u = opener.open(url)
soup = BeautifulSoup(u.read(), 'html.parser')
The previous code works as well. You just have to decode the utf-8 encoded string otherwise the header contains a byte-sequence.
from bs4 import BeautifulSoup
import urllib.request, base64, urllib.error
request = urllib.request.Request(url)
string = '%s:%s' % ('username','password')
base64string = base64.standard_b64encode(string.encode('utf-8'))
request.add_header("Authorization", "Basic %s" % base64string.decode('utf-8'))
try:
u = urllib.request.urlopen(request)
except urllib.error.HTTPError as e:
print(e)
print(e.headers)
soup = BeautifulSoup(u.read(), 'html.parser')
print(soup.prettify())

Answer 2

UTF-8 encoding might not work. You can try to use ASCII or ISO-8859-1 encoding instead.
Also, try to access the intranet site with a web browser and check how the Authorization header is different from the one you are generating.

Answer 3

Encode using "ascii". This worked for me.
import base64
import urllib.request
url = "http://someurl/path"
username = "someuser"
token = "239487svksjdf08234"
request = urllib.request.Request(url)
base64string = base64.b64encode((username + ":" + token).encode("ascii"))
request.add_header("Authorization", "Basic {}".format(base64string.decode("ascii")))
response = urllib.request.urlopen(request)
response.read() # final response string