Python for people who run networks. Articles tagged Python cover the libraries, scripts and patterns used to talk to devices, parse output and automate the boring parts.
Craft spoofed ARP and IP packets with Scapy against a Cisco IOS-XE lab, then watch Dynamic ARP Inspection drop every forgery and name the attacker's real MAC.
Netmiko, NAPALM and pyATS answer "did my change do anything?" at three different layers. Same three IOS-XE 17.18.2 routers, same lab, real captured diffs.
Config diffs tell you your text landed. They do not tell you the interface came up. Here is how pyATS and Genie snapshot live operational state, diff it across a change, and prove a rollback was clean, captured against IOS-XE 17.18.2 in CML.
Nornir gives you the inventory and the concurrency netmiko never had. NAPALM asks the router for the diff instead of guessing in Python. Captured on three IOS-XE 17.18.2 nodes, including the dest_file_system fix nobody documents.
A netmiko walkthrough built from a live capture against IOS-XE 17.18.2: connect, read, parse with TextFSM, push with send_config_set, then prove whether anything actually changed. Includes the ntc-templates key names that fail silently.