如何统计字符串中项目的重复个数？

def count_duplicates(string):
    duplicates = {}
    for item in string:
        if item in duplicates:
            duplicates[item] += 1
        else:
            duplicates[item] = 1
    return duplicates

# 示例用法
string = "abcaabbbcc"
result = count_duplicates(string)
print(result)

{'a': 3, 'b': 4, 'c': 2}