Mathematica Import/Export Format

CSV (.csv)

MIME type: text/comma-separated-values, text/csv
CSV tabular data format.
Stores records of numerical and textual information as lines, using commas to separate fields.
Commonly used in spreadsheet applications as an exchange format.
CSV is an acronym for Comma-Separated Values.
Plain text format.
Similar to TSV.

Import and Export fully support the CSV format and provide various data conversion and formatting options.

Import automatically recognizes common number formats, including C and Fortran notations.

Numbers without decimal points are imported as integers.

IMPORT AND EXPORT

Import["file.csv"] imports a CSV file, returning an array.

Export["file.csv", expr] exports a table to a CSV file.

Import["file.csv"] returns a list of lists containing strings and numbers, representing the rows and columns stored in the file.

Export["file.csv", expr] creates a CSV file from a table expr, using the CForm of non-numeric table elements.

Mathematica automatically transforms arbitrary expressions to a list of lists when exporting to CSV.

Import["file.csv", elem] imports the specified element from a CSV file.

Import["file.csv", {elem, sub_a, sub_b, ...}] imports a subelement.

Import["file.csv", {{elem₁, elem₂, ...}}] imports multiple elements.

The import format can be specified with Import["file", "CSV"] or Import["file", {"CSV", elem, ...}].

Export["file.csv", expr, elem] creates a CSV file by treating expr as specifying element elem.

Export["file.csv", {expr₁, expr₂, ...}, {{elem₁, elem₂, ...}}] treats each expr_i as specifying the corresponding elem_i.

Export["file.csv", expr, opt₁->val₁, ...] exports expr with the specified option elements taken to have the specified values.

Export["file.csv", {elem₁->expr₁, elem₂->expr₂, ...}, "Rules"] uses rules to specify the elements to be exported.

See the reference pages for full general information on Import and Export.

ImportString and ExportString support the CSV format.

NOTEBOOK INTERFACE

Save Selection As exports the selected part of a notebook as a CSV file.

ELEMENTS

General Import elements:

	"Elements"	list of elements and options available in this file
	"Rules"	full list of rules for each element and option
	"Options"	list of rules for options, properties and settings

Data representation elements:

	"Data"	two-dimensional array, representing the rows and columns of a .csv file
	"Grid"	table data as a Grid object

Import and Export use the "Data" element by default.

OPTIONS

General Export options:

	Alignment	None	how data is aligned within table columns
	CharacterEncoding	"UTF8"	raw character encoding used in the file

Possible settings for Alignment are None, Left, Center, and Right.

General Import option:

CharacterEncoding

"ASCII"

raw character encoding used in the file

Import and Export options:

	"EmptyField"	""	how to represent empty fields
	"TextDelimiters"	Automatic	string or list of strings used to delimit non-numeric fields

By default, Export delimits text fields containing commas with double-quote characters.

With an explicit setting of "TextDelimiters", Export always uses the specified string tokens to delimit text fields, effectively cycling through the list of delimiters.

"TextDelimiters" -> "\"" puts double quotes around each text field when exporting to CSV.

Double-quote characters delimiting text fields are not imported by default.

Import options:

"CurrencyTokens"	{{"$", "", "", ""}, {"c", "", "p", "F"}}	currency units to be skipped when importing numerical values
"DateStringFormat"	None	date format, given as a DateString specification
"EmptyField"	""	how to represent empty fields
"IgnoreEmptyLines"	False	whether to ignore empty lines
"Numeric"	True	whether to import data fields as numbers if possible
"NumberSigns"	{"-","+"}	strings to use for signs of negative and positive numbers
"HeaderLines"	0	number of lines to skip at the beginning of the file

Import converts table entries formatted as specified by the"DateStringFormat" option to a DateList representation of the form {y, m, d, h, m, s}.

With "Numeric" -> False, numbers will be imported as strings in the form they appear in the file.

Import automatically recognizes all common conventions for the encoding of line-separator characters.

Export option:

"TableHeadings"

None

headings for table columns and rows

"TableHeadings" can be set to the following values:

	None	no labels
	Automatic	gives successive integer labels for columns and rows
	{"col₁","col₂",...}	list of column labels
	{rhead,chead}	specifies separate labels for the rows and columns