python --创建固定字符串长度,先进先出

a = '123'def concatenate_within_limit(b, new_string):# 计算新字符串与a的长度之和a = btotal_length = len(a) + len(new_string)# 如果长度超过1024，从前面删除足够的字符if total_length > 5:diff = total_length - 5a = a[diff:] + new_string  # 删除前diff个字符，并拼接新字符串else:a += new_string  # 长度未超过1024，直接拼接新字符串# 返回处理后的areturn afor i in range(4,10):print(concatenate_within_limit(a, str(i)))