Problem with Pesky Yaks (Python)

I have decided to try and use vectors but i cannot seem to use it correctly.

The first thing that it said was ‘append’ it to the list.
so, i tried to do enemy.append("sand-yak") but that didn’t work. what should i do to fix this?

My code
# That's a lot of Yaks!
# If you are to survive, you'll need to filter out Yaks...
def removeByType(enemies, excludedType):
    tempList = []
    # Go through each enemy and check to see if its type is excludedType.
    for enemy in enemies:
        # If it isn't, 'append' it to the list.
        Vector.add(enemy.type, tempList)
    return tempList

while True:
    # Find the enemies!
    enemies = hero.findEnemies()
    # Remove those pesky Yaks.
    enemies = removeByType(enemies, "sand-yak")
    enemy = hero.findNearest(enemies)
    if enemy:
        # Now... 'remove' those enemies.

You don’t check this.

Oop, you’re using vectors. I might not be able to help in that case…
Idk if the above will still help but I’ll leave it there just in case I was (somehow) correct.