在rasperry pi 3上安装加密

Question

我是python的新手。

我正在通过Modbus模拟服务器和客户端之间的连接。我用pymodbus库做到了这一点。

我的服务器是异步服务器，我知道有必要在raspberry上安装密码学才能使其正常工作。

我找到了这些说明，并遵循了：

python apt-get install build-essential libssl-dev libffi-dev -sudo -dev；

-sudo pip安装密码术；

在那之后，我有一个错误：

Traceback (most recent call last):
File "modbus_server.py", line 4, in <module>
from pymodbus.server.async import StartTcpServer
File "/usr/local/lib/python2.7/dist-packages/pymodbus/server/async.py", line 18, in <module>
from pymodbus.internal.ptwisted import InstallManagementConsole
File "/usr/local/lib/python2.7/dist-packages/pymodbus/internal/ptwisted.py", line 5, in <module>
from twisted.conch import manhole, manhole_ssh
File "/usr/local/lib/python2.7/dist-packages/twisted/conch/manhole_ssh.py", line 14, in <module>
from twisted.conch.ssh import factory, session
File "/usr/local/lib/python2.7/dist-packages/twisted/conch/ssh/factory.py", line 17, in <module>
from twisted.conch.ssh import (_kex, transport, userauth, connection)
File "/usr/local/lib/python2.7/dist-packages/twisted/conch/ssh/transport.py", line 23, in <module>
from cryptography.hazmat.backends import default_backend
File "/usr/local/lib/python2.7/dist-packages/cryptography/hazmat/backends/__init__.py", line 7, in <module>
import pkg_resources
File "/usr/local/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 70, in <module>
import packaging.version
ImportError: No module named packaging.version

我在Windows机器上的Eclipse中尝试了相同的代码python，它可以工作。

我该如何解决这个问题？

Answer 1

缺少依赖项

运行pip install packaging