Python Compare Strings with if statements

I'm just testing out some if statements right now and I'm comparing strings. Here is my code:

#infinite loop so that function do not terminate and thread do not end.
while True:

    #Receiving from client
    data = conn.recv(1024)
    reply = 'OK...' + data
    light = 'light'
    print 'TESTING'
    if data == 'light':
        print 'Light 1 On'
    #class Command(cmd.Cmd):
    #Simple command processor example.
        #def do_greet(self, line):
            #print "hello"

        #def do_EOF(self, line):
            #return True

    #if __name__ == '__main__':
        #Command().cmdloop()
    if not data: 
        break

    conn.sendall(reply)

#came out of loop
conn.close()

I can't tell what I'm doing wrong but it doesn't seem to want to work.

Thanks!