title: How to set GeoPtProperty ?google app engine
body: <p>I have this model:</p>
  
  <pre><code>class location(ndb.Model):
        geoLocation = ndb.GeoPtProperty()
  </code></pre>
  
  <p>I am using this function to declare location model :</p>
  
  <pre><code>def careateLocationMode(cls,lon,lat):
          location1 = location()
          location1.geoLocation.lat = lat
          location1.geoLocation.lon = lon
  </code></pre>
  
  <p>but I got this error : NoneType' object has no attribute 'lat'</p>
  
  <p>what's the problem ?</p>