Python 3：使用多个相同的关键字格式化字符串，但使用唯一的字符串来替换它们

I'm wondering how to use a list to format multiple of the same keyword in Python 3.4. The way I have it set up is a user can pass in a string that has multiple keywords for names that the program will generate in their place, and the result should be a sentence with the keywords replaced with names.I'm wondering how to use a list to format multi