TODO 1:
for _ in range(n_sentences):
    rhyme = random.sample([*rhyme_groups],1)[0]
    for _ in range(2):
        for _ in range(n_random_words):
            sequence += random.sample(words,1)
        sequence += random.sample(rhyme_groups[rhyme],1)

TODO 2:
sequence = random.sample(words,1)
for i in range(sequence_length - 1):
    sequence += random.sample(transition[sequence[i]],1)

TODO 3:

transition_table = []

for w1 in transition:
    for w2 in transition[w1]:
        transition_table.append([word_to_i[w1], word_to_i[w2]])

# create the constraints
for i, v in enumerate(seq[:-1]):
    solver.Add(solver.AllowedAssignments( # also named table constraint, or extensional constraint
        (seq[i], seq[i + 1]),  # variables
        transition_table))     # table

TODO 4:
# Build the rhyme table
rhymes_table = []
for l in rhyme_groups.values():
    rhymes_table += [[word_to_i[w1],word_to_i[w2]] for w1 in l for w2 in l]

# TODO
# Create the constraints
solver.Add(solver.AllowedAssignments((seq[4], seq[9]), rhymes_table)) # First rhyme
solver.Add(solver.AllowedAssignments((seq[14], seq[19]), rhymes_table)) # second one