Error: No module named cryptography.utils

[philippe...@gmail.com]

Hi all,

I am using pymodbus on Python 2.7 under Windows.

When I use the following command: from pymodbus.server.async import StartTcpServer

I get the following error:

  File "C:\Python27\lib\site-packages\pymodbus\server\async.py", line 20, in <module>
    from pymodbus.internal.ptwisted import InstallManagementConsole
  File "C:\Python27\lib\site-packages\pymodbus\internal\ptwisted.py", line 7, in <module>
    from twisted.conch import manhole, manhole_ssh
  File "C:\Python27\lib\site-packages\twisted\conch\manhole_ssh.py", line 13, in <module>
    from twisted.conch import avatar, interfaces as iconch, error as econch
  File "C:\Python27\lib\site-packages\twisted\conch\avatar.py", line 9, in <module>
    from twisted.conch.ssh.connection import OPEN_UNKNOWN_CHANNEL_TYPE
  File "C:\Python27\lib\site-packages\twisted\conch\ssh\connection.py", line 15, in <module>
    from twisted.conch.ssh import service, common
  File "C:\Python27\lib\site-packages\twisted\conch\ssh\common.py", line 15, in <module>
    from cryptography.utils import int_from_bytes, int_to_bytes
ImportError: No module named cryptography.utils

Does anybody know where this can come from and if there is a fix?

Thanks a lot.
Philippe

[Botond Bereczki]

sudo pip install cryptography