Alright so for this problem I am meant to be writing a function that returns True if a given string contains only characters from another given string. So if I input \"bird\
This is a perfect use case of sets. The following code will solve your problem:
def only_uses_letters_from(string1, string2):
"""Check if the first string only contains characters also in the second string."""
return set(string1) <= set(string2)