New in version 2.3.
The so-called CSV (Comma Separated Values) format is the most common import and export
format for spreadsheets and databases. There is no ``CSV standard'', so the format is
operationally defined by the many applications which read and write it. The lack of a standard
means that subtle differences often exist in the data produced and consumed by different
applications. These differences can make it annoying to process CSV files from multiple
sources. Still, while the delimiters and quoting characters vary, the overall format is
similar enough that it is possible to write a single module which can efficiently manipulate
such data, hiding the details of reading and writing the data from the programmer.
The csv module implements classes to read and write tabular data in
CSV format. It allows programmers to say, ``write this data in the format preferred by
Excel,'' or ``read data from this file which was generated by Excel,'' without knowing the
precise details of the CSV format used by Excel. Programmers can also describe the CSV formats
understood by other applications or define their own special-purpose CSV formats.
The csv module's reader and writer objects read and write sequences. Programmers can also read and
write data in dictionary form using the DictReader and DictWriter classes.
Note: This version of the csv module doesn't
support Unicode input. Also, there are currently some issues regarding ASCII NUL characters.
Accordingly, all input should generally be printable ASCII to be safe. These restrictions
will be removed in the future.