Comma-separated value ("CSV") format is a common semi-standard text-based format in which fields are delimited by commas. Spreadsheets and databases are often able to export data in some variant of it. The intention is to read tables in the version of the format spoken by MS Excel amongst other applications, though the documentation on which it was based was not obtained directly from Microsoft.
The rules for data which it understands are as follows:
#
" character
(or anything else) to introduce "comment" lines.
Because the CSV format contains no metadata beyond column names, the handler is forced to guess the datatype of the values in each column. It does this by reading the whole file through once and guessing on the basis of what it has seen. This has the disadvantages:
This format cannot be automatically identified
by its content, so in general it is necessary
to specify that a table is in
CSV
format when reading it.
However, if the input file has
the extension ".csv
" (case insensitive)
an attempt will be made to read it using this format.
An example looks like this:
RECNO,SPECIES,NAME,LEGS,HEIGHT,MAMMAL 1,pig,Pigling Bland,4,0.8,true 2,cow,Daisy,4,2.0,true 3,goldfish,Dobbin,,0.05,false 4,ant,,6,0.001,false 5,ant,,6,0.001,false 6,queen ant,Ma'am,6,0.002,false 7,human,Mark,2,1.8,true
See also ECSV as a format which is similar and capable of storing more metadata.