def pcapname(dev):
    """Get the device pcap name by device name or Scapy NetworkInterface

    """
    if isinstance(dev, NetworkInterface):
        if dev.is_invalid():
            return None
        return dev.pcap_name
    try:
        return IFACES.dev_from_name(dev).pcap_name
    except ValueError:
        return IFACES.dev_from_pcapname(dev).pcap_name
Get the device pcap name by device name or Scapy NetworkInterface