From the passage identify the sacred animals of Apollo. Display the results in a comma separated format.

Context: Apollo 

God of music, arts, knowledge, healing, plague, prophecy, poetry, manly beauty, and archery. He is the son of Zeus and Leto, and the twin brother of Artemis. Both Apollo and Artemis use a bow and arrow. Apollo is depicted as young, beardless, handsome and athletic. In myth, he can be cruel and destructive, and his love affairs are rarely happy. He is often accompanied by the Muses. His most famous temple is in Delphi, where he established his oracular shrine. His signs and symbols include the laurel wreath, bow and arrow, and lyre. His sacred animals include roe deer, swans, and pythons. Some late Roman and Greek poetry and mythography identifies him as a sun-god, equivalent to Roman Sol and Greek Helios.

Answer: roe deer, swans, pythons