Question

write a function

firstLetterWords(words)

that takes as a parameter a list of strings named words and returns a dictionary with lower case letters as keys. But now associate with each key the list of the words in words that begin with that letter. For example, if the list is ['ant', 'bee', 'armadillo', 'dog', 'cat'], then your function should return the dictionary {'a': ['ant', 'armadillo'], 'b': ['bee'], 'c': ['cat'], 'd': ['dog']}.

Answer 1

def firstLetterWords(words):
    d = dict()
    for x in words:
        if not d.get(x[0]):
            d[x[0]] = [x]
        else:
            lst = d[x[0]]
            lst.append(x)
            d[x[0]] = lst
    return d

print(firstLetterWords(['ant', 'bee', 'armadillo', 'dog', 'cat']))

{'a': ['ant', 'armadillo'], 'b': ['bee'], 'd': ['dog'], 'c': ['cat']}