python 2.7 - Creating a bootstrap table with data from MySQLdb in flask -

hello guys trying create bootstrap table data mysql database. getting error local variable data referenced before assignment. please code below.

app.py code

   @app.route("/viewsingle", methods=['post','get'])    def singleview():      if request.method=="post":         if request.form['submit']=="view continent":            c,conn = connection()            c.execute('''select * country''')            data = c.fetchall ()            c.close ()             conn.close ()      return render_template("view.html",data=data) 

view.html

    <div class = "one1-div">    <div class ="container">    <form class="form-group" action="{{ url_for('singleview') }}"          method=post>     <table class="table">      <thead>       <tr>         <th>firstname</th>         <th>lastname</th>         <th>email</th>       </tr>     </thead>    <tbody>     {%for row in data%}      <tr class="success">       <td>{{row[0]}}</td>       <td>{{row[1]}}</td>       <td>{{row[2}}</td>     </tr>     {%endfor%}   </tbody>   </table>   </form> 

it seems not working hoping on getting value [0] , [1] tuple( data= c.fetchall()) table error local variable 'data' referenced before assignment.but if change return render_template("view.html", data=data) return render_template("view.html") runs no error empty noting print. there better way or missing something. please advice or help. link code are. http://pastebin.com/u/itetteh/1 thanks