Python Firewall Rule Automation

I need a clean, well-commented Python script that can log in to both Cisco and Juniper firewalls and handle configuration changes focused solely on firewall rules. The goal is to automate the creation of new rules and the modification of existing ones while leaving deletion out of scope for now.

The script should connect over SSH (or the device’s API if you find it more reliable), authenticate with credentials I will supply, push the intended rule set, and then confirm the change took effect. I am comfortable with libraries such as Netmiko, Paramiko, or Napalm, so feel free to choose whichever one best fits both vendors; just note your choice in the code header.

For quick validation, include a simple YAML or JSON file where I can define rule parameters—source, destination, port, protocol, action—and have the script read from that file before building the commands. Output from each step should be echoed to the console and written to a log file so I have clear evidence of success or any errors per device.

Deliverables:
• Python script with clear functions for rule creation and rule modification
• Sample data file (YAML/JSON) illustrating the expected rule format
• Short README explaining prerequisites, how to run, and rollback guidance if a push fails

I have test firewalls ready, and I’ll verify by running the script against them. Once the script reliably creates and edits rules on both Cisco and Juniper boxes, the task will be considered complete.