Parse arbitrary key:value file.

parse_file.py

identifiers = ["IP Address", "Vlan", "Subnet Mask"]  # etc.  Define what you want to grab here

def parse_line(line):
    # the second argument means only take the first split. e.g. "a:b:c" becomes "a", "b:c"
    key, value = line.split(":", 1)
    # if the identifier is one we care about
    if key in identifiers:
        return key, value
    return None, None

with open("filename.txt", 'r') as f:
    lines = f.readlines()

for line in lines:
    k, v = parse_line(lines)
    # If you want to parse multiple interfaces
    # in the same file, watch out for key collisions
    if k:
        info[k] = v

print(info)