'unicode' object is not callable

import lxml.html
import urllib

num=1
while(num<=5):
    url = "http://www.sdzk."
    final_url = "http://www.sdzk."+str(num)+".htm"
    page = urllib.urlopen(final_url)
    str = page.read().decode("gb2312")


    doc = lxml.html.fromstring(str)
    name_ele = doc.cssselect("td")


    i = 26
    plan = 0
    post = 0
    while(i<len(name_ele)):
        if((i-26)%11==0):
            try:
                plan = int(name_ele[i+6].text)
                post = int(name_ele[i+8].text)
                print "%s,%d" % (name_ele[i].text,plan-post)
            except TypeError:
                print "None"
        i = i+1
   
    num = num+1

try:
   final_url = "http://www.sdzk."+str(num)+".htm"
except ValueError:
   final_url = "http://www.sdzk."+num+".htm"