title: geopandas POLYGON coordinates to x,y coordinate columns
body: <p>I have a geopandas dataframe of the type:</p>
  <pre><code> id  \
  0  028f342a-b26f-4e36-b5d1-25d3428cac2f   
  
                                                   add  
  0  POLYGON ((33.78148 3.50903, 33.12417 3.50903, ... 
  </code></pre>
  <p>Here is the entire POLYGON:</p>
  <pre><code>;id;add
  0;028f342a-b26f-4e36-b5d1-25d3428cac2f;POLYGON ((33.781475 3.5090296, 33.1241675 3.5090296, 33.1241675 4.392868066666667, 33.781475 4.392868066666667, 33.781475 3.5090296))
  </code></pre>
  <p>What I wish to do is to extract all <code>x</code> and <code>y</code> coordinates of the polygon corners into 2 columns. So, what I have tried is (This code is meant for the entire dataframe):</p>
  <pre><code>List_Mvv_id = list(set(df['id']))
  
  Full =[]
  for i in List_Mvv_id:
      df = df[df['id']==i]
      P = df['add'].iloc[0]
      print(P)
      for x,y in P.exterior.coords:
          df['x'] = x
          df['y'] = y
  
          Full.append(df)
  </code></pre>
  <p>However, it only returns the first coordinates of the polygon:</p>
  <pre><code>                                     id  \
  0  028f342a-b26f-4e36-b5d1-25d3428cac2f   
  0  028f342a-b26f-4e36-b5d1-25d3428cac2f   
  0  028f342a-b26f-4e36-b5d1-25d3428cac2f   
  0  028f342a-b26f-4e36-b5d1-25d3428cac2f   
  0  028f342a-b26f-4e36-b5d1-25d3428cac2f   
  
                                                   add          x        y  
  0  POLYGON ((33.78148 3.50903, 33.12417 3.50903, ...  33.781475  3.50903  
  0  POLYGON ((33.78148 3.50903, 33.12417 3.50903, ...  33.781475  3.50903  
  0  POLYGON ((33.78148 3.50903, 33.12417 3.50903, ...  33.781475  3.50903  
  0  POLYGON ((33.78148 3.50903, 33.12417 3.50903, ...  33.781475  3.50903  
  0  POLYGON ((33.78148 3.50903, 33.12417 3.50903, ...  33.781475  3.50903  
  </code></pre>
  <p>I tried also this approach:</p>
  <pre><code>def coord_lister(geom):
      coords = list(geom.exterior.coords)
      return (coords)
  
  coordinates_list = df.geometry.apply(coord_lister)
  </code></pre>
  <p>But I got stuck on extracting the x,y coordinates.</p>
  <p>Grateful for any insights.</p>