Determining physical ethernet device

[purpleidea]

I'm running this code:

package main

import "fmt"
import "github.com/vishvananda/netlink"

func main() {
	links, err := netlink.LinkList()
	if err != nil {
		panic(err)
	}
	fmt.Printf("links: %+v\n", links)
	for i, link := range links {
		fmt.Printf("link(%d): %+v\n", i, link.Type())
		attrs := link.Attrs()
		fmt.Printf("link(%d): Name: %+v\n", i, attrs.Name)
		fmt.Printf("link(%d): Name: %+v\n", i, attrs.Name)
	}
}

I've got loopback, one bridge, one wifi device, and one physical ethernet port. I've printed out the output from the wifi and ethernet device. I've also removed most identical fields and censored the mac addresses:

&{Index:2 MTU:1500 TxQLen:1000 Name:enp0s31f6 HardwareAddr:xx:xx:xx:xx:xx:xx Flags:up|broadcast|multicast RawFlags:4099  Alias: Statistics:0xc0000da180  Xdp:0xc0000c2090 EncapType:ether  OperState:down }

&{Index:3 MTU:1500 TxQLen:1000 Name:wlp0s20f3 HardwareAddr:yy:yy:yy:yy:yy:yy Flags:up|broadcast|multicast RawFlags:69699 Alias: Statistics:0xc0000da300  Xdp:0xc0000c20a8 EncapType:ether OperState:up }

Apart from parsing the name, I don't know how to tell programatically which is the physical ethernet device and which is wifi. Is there a way?

Thanks!