def bounds(gdf):
    """Calculates the bounding coordinates (left, bottom, right, top) in the given GeoDataFrame.
    
    Args:
         gdf: A GeoDataFrame containing the input points.
         
    Returns:
          An array [minx, miny, maxx, maxy] denoting the spatial extent. 
    """
        
    bounds = gdf.total_bounds  
    return bounds