See the below example which can verify your ldap connection.
import ldap3 as ldap
SERVER_NAME = 'ldap://host:389'
DN = 'uid='
USERNAME = 'user'
PASSWORD = 'password'
server = ldap.Server(SERVER_NAME)
connection = ldap.Connection(server, user='{}\\{}'.format(DN, USERNAME), password=PASSWORD)
connection.open()
if connection.bind():
print('Authenticated!')
else:
print('Not Authenticated')
print(connection.result)