| Comma-separated values | |
| Extension: | .csv |
| Mime: | text/csv text/comma-separated-values (deprecated) |
CSV is one implementation of a delimited text file, which uses a comma to separate values (where many implementations of CSV import/export tools allow an alternate separator to be used; as is shown in the MS Access screen shot, below). However CSV differs from other delimiter separated file formats in using a " (double quote) character around fields that contain reserved characters (such as commas or newlines). Most other delimiter formats either use an escape character such as a backslash, or have no support for reserved characters.
In computer science terms, this type of format is called a "flat file" because only one table can be stored in a CSV file. Most systems use a series of tables to store their information, which must be "flattened" into a single table, often with information repeated over several rows, to create a delimited text file.
While no formal specification for CSV exists, RFC 4180 describes a common format and establishes "text/csv" as the MIME type registered with the IANA. Another relevant specification is provided by Fielded Text which also covers the CSV format.
Many informal documents exist that describe the CSV format. How To: The Comma Separated Value (CSV) File Format provides an overview of the CSV format in the most widely used applications and explains how it can best be used and supported.
The basic rules are as follows:
CSV is a delimited data format that has fields/columns separated by the comma character and records/rows separated by newlines. Fields that contain a special character (comma, newline, or double quote), must be enclosed in double quotes. However, if a line contains a single entry which is the empty string, it may be enclosed in double quotes. If a field's value contains a double quote character it is escaped by placing another double quote character next to it. The CSV file format does not require a specific character encoding, byte order, or line terminator format.
1997,Ford,E350
1997, Ford , E350 same as
1997,Ford,E350
1997,Ford,E350,"Super, luxurious truck"
1997,Ford,E350,"Super ""luxurious"" truck"
1997,Ford,E350,"Go get one now they are going fast"
1997,Ford,E350," Super luxurious truck "
"1997","Ford","E350"
Year,Make,Model 1997,Ford,E350
2000,Mercury,Cougar
| 997 | Ford | E350 | ac, abs, moon | 3000.00 |
| 1999 | Chevy | Venture "Extended Edition" | 4900.00 | |
| 1996 | Jeep | Grand Cherokee | MUST SELL! air, moon roof, loaded |
4799.00 |
The above table of data may be represented in CSV format as follows:
1997,Ford,E350,"ac, abs, moon",3000.00
1999,Chevy,"Venture ""Extended Edition""",,4900.00 1996,Jeep,Grand Cherokee,"MUST SELL!
air, moon roof, loaded",4799.00
This CSV example illustrates that:
See main article: CSV application support.
The CSV file format is very simple and supported by almost all spreadsheets and database management systems. Many programming languages have libraries available that support CSV files. Even modern software applications support CSV imports and/or exports because the format is so widely recognized. In fact, many applications allow .csv-named files to use any delimiter character.