访问数据集问题

请问代码：filename = "file_location/request_information_city_name.csv"应该如何修改，精确到数据集文件的哪一级。
同样请问如下代码该如何修改：
filename = "file_location/machine0.csv"
filename = "file_location/machine1.csv"
filename = "file_location/machine2.csv"
filename = "file_location/machine3.csv"
filename = "file_location/machine4.csv"
filename = "file_location/machine5.csv"。
其中的file_location/machine0.csv该替换成数据集文件的哪一级。
谢谢！