title: Turn geometry column into lat/long columns in Geodataframe
body: <p>I have a Geodataframe with a 'geometry' column in which I have point geometries, e.g. POINT (-0.01334 51.52883). I need to extract the latitude and longitude and add it as new columns in the dataframe. </p>
  
  <p>I tried using </p>
  
  <pre><code>df['lon'] = df['geometry'].x
  df['lat'] = df['geometry'].y
  </code></pre>
  
  <p>but it gives me a SettingWithCopyWarning and I'm not sure why. Can anybody help please? Thank you!</p>