human
I wrote the below code

    def _get_number(if_name):
        digits = ''
        for char in if_name:
            if (char.isdigit() or (char == '/')):
                digits += char
        return digits
    if if_name.lower().startswith('et'):
        if_type = 'Ethernet'
    elif if_name.lower().startswith('vl'):
        if_type = 'Vlan'
    elif if_name.lower().startswith('lo'):
        if_type = 'loopback'
    elif if_name.lower().startswith('po'):
        if_type = 'port-channel'
    elif if_name.lower().startswith('nv'):
        if_type = 'nve'
    else:
        if_type = None
    number_list = if_name.split('    ')
    if (len(number_list) == 2):
        number = number_list[(-1)].strip()
    else:
        number = _get_number(if_name)
    if if_type:
        proper_interface = (if_type + number)
    else:
        proper_interface = if_name
    return proper_interface

What's a good function header?

=====
Here's a good function header?
assistant
#Here's a good function header.

def normalize_interface(if_name):