Here is an interesting video for Network Engineers have experience on Cisco devices and want to learn Arista switching. I tried Arista vEOS on VirtualBox. Cisco VIRL, GNS3 and UnetLab also support Arista image.
Scapy is a well known packet manipulation framework developed in Python. It could be quite useful for people want to understand network at people level. Though it is used mostly by security engineers or penetration testers but i also suggest for Network Engineers apart from using Wireshark. Below are the few resources from where you can learn