Python on the Web - Cookies (
Page 3 of 6 )
Next up we'll use Python's 'Cookie' module to do a little baking!
(Ironically I suck at making real cookies.)
>>> import
Cookie
>>> cookie = Cookie.SimpleCookie()
>>>
cookie['number1'] = 'some values'
>>> cookie['number2'] = 'some
values'
>>> cookie['number3'] = 'some values'
>>>
cookie['number3']['expires'] = 3600
>>> print cookie
Set-Cookie:
number1="some values";
Set-Cookie: number2="some values";
Set-Cookie:
number3="some values"; expires=Fri, 30-Jan-2004 12:03:20
GMT;
Ok, you have to agree, setting cookies couldn't be much simpler, and the
'Cookie' module wraps it up nicely. The difficulty comes when you want to
retrieve your values... ok maybe I'm exaggerating a little here.
#!/usr/bin/env python
import os
def monster():
if
'HTTP_COOKIE' in os.environ:
cookies =
os.environ['HTTP_COOKIE']
cookies = cookies.split(';
')
handler = {}
for cookie in
cookies:
cookie =
cookie.split('=')
handler[cookie[0]] =
cookie[1]
return
handler
if __name__ == '__main__':
import
Cookie
cookie =
Cookie.SimpleCookie()
cookie['monster'] = 'cookievalue'
print
cookie
print 'Content-Type:
text/htmln'
print 'Hit refresh to see the cookie!!!<br
/>'
print 'Hewwo, im the cookie', monster()
This is all about parsing the 'HTTP_COOKIE' header and inserting the
cookie values into a dictionary.
We start by importing the 'os' module into our program and defining the monster() function -- this checks
if the 'cookies' string exists or not. If it does then we split it, leaving us
with a list of 'key=value' strings. After that all we have left to do is loop
over the list and split the values again, placing them into the dictionary.
Ok finally let's do something a little useful with our cookies... and in
keeping with our final example, we're going to create a counter function, which
allows you to set limits on different processes. Observe and enjoy.
#!/usr/bin/env python
import Cookie, os
def limits(count):
if
'HTTP_COOKIE' in os.environ:
cookies =
os.environ['HTTP_COOKIE']
cookies = cookies.split(';
')
handler = {}
for cookie in
cookies:
cookie =
cookie.split('=')
handler[cookie[0]] = cookie[1]
if 'count' in
handler:
number =
int(handler['count'])
if number <
count:
cookie =
Cookie.SimpleCookie()
cookie['count'] = number +
1
cookie['count']['expires'] =
86400
print cookie
return
True
else:
print
Cookie.SimpleCookie('count=1')
return True
if __name__ == '__main__':
if limits(5):
print 'user
was under their limit, do this...'
else:
print 'user was over their
limit, do nothing!'
The start of this is exactly the same as in our monster() function except that if there
are no cookies set, then we create one and set its value to one. If there are
any cookies to unpack, then we check for 'count' in the handler dictionary and
type-cast its value to a 'number' using int()... 'number' is then compared to
the 'count' variable to check if the user is under or over their limit. Provided
they're under their limit, then we update the cookie and set the expiry date to
24 hours before returning True; this is done so we can use if-else blocks to
control the users access.