title: pymssql: executemany value error - expected a simple type, a tuple or a list
body: <pre><code>grpidx_data=[]
  for i in range(0,len(data1)):
      grpidx_data.append((data1.loc[i,'price'],data1.loc[i,'id']))
  cur.executemany("insert into grpidx values (%s,%s)",grpidx_data)
  </code></pre>
  
  <p>I use python3.3 and pymssql. I want to import data from python to MSSQL. grpidx_data's type is <strong>list(tuple)</strong>,like[(12,1),(34,2),...], I run the code above then got the error:</p>
  
  <blockquote>
    <p>ValueError: expected a simple type, a tuple or a list</p>
  </blockquote>
  
  <p>If I just use the data which type is <strong>list(tuple)</strong>, the code works fine. But when I use for loop got the data, even its type also <strong>list(tuple)</strong>,its not working.</p>
  
  <p>So How to solve this problem? </p>
  
  <p>Thanks!</p>