将数据转成CSV格式

import csv
from distutils.log import warn as printf

DATA = (
    (9, 'Web Clients and Servers', 'base64, urllib'),
    (10, 'Web Programming: CGI & WSGI', 'cgi, time, wsgiref'),
    (13, 'Web Services', 'urllib, twython'),
)

printf('*** WRITING CSV DATA')
f = open('bookdata.csv', 'w')
writer = csv.writer(f)
for record in DATA:
    writer.writerow(record)
f.close()

printf('*** REVIEW OF SAVED DATA')
f = open('bookdata.csv', 'r')
reader = csv.reader(f)
for chap, title, modpkgs in reader:
    printf('Chapter %s: %r (featuring %s)' % (
        chap, title, modpkgs))

f.close()

csv.writer()函数需要一个打开的文件（或者类文件）对象，返回一个writer对象，writer提供了writerrow()方法，可以用来在打开的文件中逐行写入逗号分隔的数据。