The Automation1 Python API requires the aenum pip package version 3.1.3 or newer. If this package is not installed, pip will try to download it, which will throw an error about build dependencies if your PC is offline. You can manually install aenum by downloading it from an internet-connected PC and moving it to your offline PC. Use the pip install command to install the aenum package.
If you already have aenum installed and receive the same error installing the Python API, you can navigate to the directory: C:\Program Files\Aerotech\Automation1-MDK\APIs\Python\automation1 and run python setup.py install. This may still give an error message stating that it could not find aenum to install, but it should still install the automation1 package.