Write a program to strip the punctuation from a string. The input to the program should be a string of characters including punctuation; the output should be a string in which the punctuation is removed.
编一个程序,从 string 对象中去掉标点符号。要求输入到程序的字符串必须含有标点符号,输出结果则是去掉标点符号后的 string 对象。