words = ['apples', 'bananas', 'tofu', 'cats']
def spam(words):
if words:
return ", ".join(words[:-1]) + ", and " + words[-1]
print spam(words)
d29yZHMgPSBbJ2FwcGxlcycsICdiYW5hbmFzJywgJ3RvZnUnLCAnY2F0cyddCmRlZiBzcGFtKHdvcmRzKToKCWlmIHdvcmRzOgogICAgICAgICByZXR1cm4gIiwgIi5qb2luKHdvcmRzWzotMV0pICsgIiwgYW5kICIgKyB3b3Jkc1stMV0KcHJpbnQgc3BhbSh3b3Jkcyk=