go如何使用string替换

直接上代码，看懂案例就能懂如何使用

Java

 String key="";
 key.replace(旧字符串,新字符串);

Go

baseUrl := "http://{username}:{password}@{host}:{port}/RPC2"
r := strings.NewReplacer("{username}", username, "{password}", password, "{host}", host, "{port}", port)
server := r.Replace(baseUrl)

Python

server = "{host}:{port}/RPC2".format(host=host, port=port)