Reputation: 3673
I have a method which writes into a database the username and password of user who wish to register. Before storing the username and password they have provided into the database, i want to check if the username they have chosen already exist in either the "pending" list, or the approved "contacts" list.
Here is the code I used to do that:
@cherrypy.expose
def writePending(self, username=None, password=None, message=None, signin=None):
""" Add request of friendship into a database which stores all
pending friendships.
"""
page = get_file(staticfolder + "/html/friendingPage.html")
if username != "" and password != "" and message !="":
con = lite.connect('static/database/Friendship.db')
cur = con.cursor()
with con:
cur.execute("CREATE TABLE IF NOT EXISTS pending(user TEXT, pass TEXT, info TEXT)")
cur.execute("CREATE TABLE IF NOT EXISTS contacts(user TEXT, pass TEXT)")
"Check to see if the username is already registered"
cur.execute("Select * from pending where user = ?", (username, ))
check1=cur.fetchone()
cur.execute("Select * from contacts where user = ?", (username, ))
check2=cur.fetchone()
if check1[0] != None:
page = page.replace("$Error", "The ID you used is still pending for friendship")
elif check2[0] != None:
page = page.replace("$Error", "The ID you used is already added as a contact")
else:
cur.execute("CREATE TABLE IF NOT EXISTS pending(user TEXT, pass TEXT, info TEXT)")
cur.execute("INSERT INTO pending VALUES(?, ?, ?)", (username, password, message))
page = get_file(staticfolder + "/html/thankYouPage.html")
else:
page = get_file(staticfolder + "/html/friendingPage.html")
page = page.replace("$Error", "You Must fill out all fields to proceed")
return page
However, I would get a message that
Traceback (most recent call last):
File "/usr/lib/pymodules/python2.7/cherrypy/_cprequest.py", line 606, in respond
cherrypy.response.body = self.handler()
File "/usr/lib/pymodules/python2.7/cherrypy/_cpdispatch.py", line 25, in __call__
return self.callable(*self.args, **self.kwargs)
File "proj1base.py", line 540, in writePending
if type(check1[0]) != None:
TypeError: 'NoneType' object is not subscriptable
I am wondering what I can do to avoid that?
Thanks.
Upvotes: 3
Views: 11472
Reputation: 2133
fetchone()
returns None
if there isn't a row. You can code like this:
if check1:
...do something with check1, like check1[0]...
else:
.. means no row
Upvotes: 1
Reputation: 8876
In your example, check1
will be None
, so you can't use [0]
on it. You could do something like this:
if check1 is not None:
(error response)
Or instead just use cur.rowcount
instead of cur.fetchone()
:
if cur.rowcount > 0:
(error response)
Upvotes: 6