title: Psycopg2 execute tuple index out of range
body: <p>I am very new to python and this is my first programming language. This is my first shot at using SQL as well as psycopg2. Any "dumb" advice is much appreciated!</p>
  
  <p>I am not sure what the problem is. My research tells me im feeding too few or too many arguments to the <code>cursor.execute(INSERT...</code> but i have tried a number of different counts and can't seem to get any working correctly. From my point of view the <code>cursor.execute(CREATE...</code> creates a table with 6 columns and i am passing 6 args to it.</p>
  
  <pre><code>from lxml import html  # Used to parse XML
  import requests #used to service API request
  
  itemtypeid1 = 34
  itemtypeid2 = 35
  regionid = 10000002
  
  webpage = requests.get('http://api.eve-central.com/api/marketstat?typeid=%i&amp;typeid=%i&amp;regionlimit=%i' % (
  itemtypeid1, itemtypeid2, regionid))
  
  if webpage.status_code == 200:
      data = html.fromstring(webpage.content)
      for item in data.iter('type'):
  
  
          buy_dict = {node.tag: node.text for node in item.xpath("buy/*")}
          sell_dict = {node.tag: node.text for node in item.xpath("sell/*")}
  
          #Variables for output
          itemid = (item.get("id"))
          buymin = buy_dict['min']
          buymax = buy_dict['max']
          buymedian = buy_dict['median']
          buyvolume = buy_dict['volume']
          buyaverage = buy_dict['avg']
  
  #Fail if api webpage unavaliable
  else:
          print "Webpage unavaliable"
          Webpage.raise_for_status()
  
  
  #############################################################################
  
  
  import psycopg2
  
  connection = psycopg2.connect(database='evemarketdata', user='postgres', password='black3car')
  
  #open a cursor to perform DB operations
  cursor = connection.cursor()
  
  #create new table
  cursor.execute("CREATE TABLE arkonor (itemid integer primary key, min integer, max integer, median integer, volume integer, average integer);")
  
  #Insert row data into DB table
  cursor.execute("""INSERT INTO arkonor (typeid, min, max, median, volume, average)
       VALUES (%s, %s, %s, %s, %s, %s, %s, %s)""",
       ('itemid', 'buymin', 'buymax', 'buymedian', 'buyvolume', 'buyaverage'))
  
  
  #Commits all changes does with cursor
  #connection.commit()
  </code></pre>
  
  <p>results in</p>
  
  <pre><code> Traceback (most recent call last):
  
   File "E:\Eve Spreadsheets\Python\PostgreConnect.py", line 49, in &lt;module&gt;
  
  ('itemid', 'buymin', 'buymax', 'buymedian', 'buyvolume', 'buyaverage'))
  
  IndexError: tuple index out of range
  </code></pre>