cannot install

[davisbra]

when i trying to install flowing error appears:
Installed /usr/local/lib/python3.5/dist-packages/commandment-0.1-py3.5.egg
Processing dependencies for commandment==0.1
error: cryptography 1.2.3 is installed but cryptography>=2.2.1 is required by {'PyOpenSSL'}
how to resolve this error?

[the-c0d3r]

That means your cryptography package is lower than the required version 2.21. So you can use pip to upgrade your cryptogrpahy.

pip install --upgrade cryptography

But a better approach is to use virtualenv to install and maintain python projects in order to avoid such conflicts.