Comma-separated files are a format frequently used for exporting data
from databases and spreadsheets. Python 2.3 adds a parser for
comma-separated files.
Comma-separated format is deceptively simple at first glance:
Costs,150,200,3.95
Read a line and call line.split(','): what could be simpler?
But toss in string data that can contain commas, and things get more
complicated:
"Costs",150,200,3.95,"Includes taxes, shipping, and sundry items"
A big ugly regular expression can parse this, but using the new
csv package is much simpler:
import csv
input = open('datafile', 'rb')
reader = csv.reader(input)
for line in reader:
print line
The reader function takes a number of different options.
The field separator isn't limited to the comma and can be changed to
any character, and so can the quoting and line-ending characters.
Different dialects of comma-separated files can be defined and
registered; currently there are two dialects, both used by Microsoft Excel.
A separate csv.writer class will generate comma-separated files
from a succession of tuples or lists, quoting strings that contain the
delimiter.
