如何计算字符串中的重复字符

def count_duplicate_chars(s):
    char_count = {}
    for char in s:
        if char in char_count:
            char_count[char] += 1
        else:
            char_count[char] = 1
    
    duplicates = {char: count for char, count in char_count.items() if count > 1}
    return duplicates

# 示例
input_string = "hello world"
duplicates = count_duplicate_chars(input_string)
print(duplicates)  # 输出: {'l': 3, 'o': 2}

input_string = "Hello World"
s = input_string.lower()
duplicates = count_duplicate_chars(s)
print(duplicates)  # 输出: {'l': 3, 'o': 2}

def count_duplicate_chars(s):
    char_count = {}
    for char in s:
        if char.isalpha():  # 只处理字母字符
            if char in char_count:
                char_count[char] += 1
            else:
                char_count[char] = 1
    
    duplicates = {char: count for char, count in char_count.items() if count > 1}
    return duplicates

input_string = "Hello, World!"
duplicates = count_duplicate_chars(input_string)
print(duplicates)  # 输出: {'l': 3, 'o': 2}