TSV 是Tab-separated values的缩写，即制表符分隔值。

相对来说CSV，Comma-separated values（逗号分隔值）更常见一些。

TSV与CSV的区别：

1）从名称上即可知道，TSV是用制表符（Tab,'\t'）作为字段值的分隔符；CSV是用半角逗号（','）作为字段值的分隔符；

2）IANA规定的标准TSV格式，字段值之中是不允许出现制表符的。

Python对TSV文件的支持：

Python的csv模块准确的讲应该叫做dsv模块，因为它实际上是支持范式的分隔符分隔值文件（DSV，delimiter-separated values）的。

delimiter参数值默认为半角逗号，即默认将被处理文件视为CSV。

当delimiter='\t'时，被处理文件就是TSV。

详情见这里：http://docs.python.org/library/csv.html

关于TSV更详细的说明：http://en.wikipedia.org/wiki/Tab-separated_values

A tab-separated values file is a simple text format for a database table. Each record in the table is one line of the text file. Each field value of a record is separated from the next by a tab stop character – it is a form of the more general delimiter-separated values format.

TSV is a simple file format that is widely supported, so it is often used to move tabular data between different computer programs that support the format. For example, a TSV file might be used to transfer information from a database program to a spreadsheet.

TSV is an alternative to the common comma-separated values (CSV) format, which often causes difficulties because of the need to escape commas – literal commas are very common in text data, but literal tab stops are infrequent in running text. The IANA standard for TSV achieves simplicity by simply disallowing tabs within fields.