如何在Python 3中查找字符串中的重复项？

def find_duplicates(string):
    char_count = {}
    duplicates = []

    for char in string:
        if char in char_count:
            char_count[char] += 1
        else:
            char_count[char] = 1

    for char, count in char_count.items():
        if count > 1:
            duplicates.append(char)

    return duplicates

# 示例用法
string = "abcaabbcc"
result = find_duplicates(string)
print(result)  # 输出 ['a', 'b', 'c']