FormatWords.py

'''
Description:
Complete the method so that it formats the words into a single comma separated value. The last word should be separated by the word 'and' instead of a comma. The method takes in an array of strings and returns a single formatted string. Empty string values should be ignored. Empty arrays or null/nil values being passed into the method should result in an empty string being returned.

formatWords(['ninja', 'samurai', 'ronin']) // should return "ninja, samurai and ronin"
formatWords(['ninja', '', 'ronin']) // should return "ninja and ronin"
formatWords([]) // should return ""
'''

def format_words(words):
    if not words or words == ['']:
        return ''
    words = [i for i in words if i != '' ]
    if len(words) == 1:
        return words[0]
    return ', '.join(words[:-1]) + ' and ' + words[-1]

print(format_words(['one','two','three']))