如何计算可以包含列表和字符串的变量中的字符数

def count_characters(variable):
    total_count = 0
    
    if isinstance(variable, list):
        for item in variable:
            if isinstance(item, str):
                total_count += len(item)
            elif isinstance(item, list):
                total_count += count_characters(item)
    elif isinstance(variable, str):
        total_count += len(variable)
    
    return total_count

# 示例变量
example_variable = ["hello", "world", ["nested", "list"], "example"]

# 计算字符数
result = count_characters(example_variable)
print("总字符数:", result)