<prompt> Design a function to count the number of unique characters in a string.string Butterflies  <response>: Here is one way to count the number of unique characters in a string using Python:def count_unique_charsstring: unique_chars setstring return lenunique_charsTo use this function with the example input you provided, we can call the function like this:string Butterfliescount count_unique_charsstringprintfNumber of unique characters in string is: countThis would output:Number of unique characters in Butterflies is: 9 