"""Our own little animal farm."""
import sys
def add_animal(farm, animal):
farm.add(animal)
return farm
def main(animals):
farm = set()
for animal in animals:
farm = add_animal(farm, animal)
print("We've got some animals on the farm:", ','.join(farm) + '.')
if __name__ == '__main__':
if len(sys.argv)==1:
print('Pass at least one animal type!')
sys.exit(1)
main(sys.argv[1:])