# import class and constants
from ldap3 import Server, Connection, ALL, MODIFY_REPLACE

# define the server
s = Server('servername', get_info=ALL)  # define an unsecure LDAP server, requesting info on DSE and schema

# define the connection
c = Connection(s, user='user_dn', password='user_password')
c.bind()

# perform the Modify operation
c.modify('cn=user1,ou=users,o=company',
         {'givenName': [(MODIFY_REPLACE, ['givenname-1-replaced'])],
          'sn': [(MODIFY_REPLACE, ['sn-replaced'])]})
print(c.result)

# close the connection
c.unbind()