all Python 3urllib.requestterm

urllib.request.HTTPBasicAuthHandler

authentication

Answers a 401 with WWW-Authenticate: Basic by repeating the request with the login and password from the password manager.

Syntax

urllib.request.HTTPBasicAuthHandler(password_mgr=None)

The first request always goes out without the password, and only a 401 triggers a retry — a server answering 403 or 404 instead never gets the password (use HTTPPasswordMgrWithPriorAuth then). If the realm in add_password does not match the server's, you get HTTPError 401. Without an argument it creates its own empty manager — add the password with handler.add_password().

Examples

import email.message, io, urllib.error, urllib.request, urllib.response
def reply(req, code, body=b'', **headers):
    msg = email.message.Message()
    for name, value in headers.items():
        msg[name.replace('_', '-')] = value
    resp = urllib.response.addinfourl(io.BytesIO(body), msg, req.full_url, code)
    resp.msg = 'demo'
    return resp
class Server(urllib.request.BaseHandler):
    handler_order = 100
    def http_open(self, req):
        auth = req.get_header('Authorization')
        print('Authorization:', auth)
        if auth:
            return reply(req, 200, b'ok')
        return reply(req, 401, WWW_Authenticate='Basic realm="api"')
mgr = urllib.request.HTTPPasswordMgrWithDefaultRealm()
mgr.add_password(None, 'http://example.com/', 'u', 'p')
opener = urllib.request.build_opener(Server, urllib.request.HTTPBasicAuthHandler(mgr))
print(opener.open('http://example.com/secret').read())
# → Authorization: None / Authorization: Basic dTpw / b'ok'

See also

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