웹 파이선 프로그래밍

sentence = str(input("Input a sentence: "))

letter = str(input("Input a letter: "))

def calcCharacterFromString(sentence, letter):

    if sentence.count(letter) >= 1:

        return sentence.count(letter)

    elif sentence.count(letter) <1:

        return "Error"

print(calcCharacterFromString(sentence, letter))    

여기서 실행시켜서 input 창에

input a sentence: "I like you"

input a letter: "o"

하면 

Error가 뜨는데, 밑에 input에 쌍따옴표를 빼고

input a sentence: "I like you"

input a letter: o