code: def load_sgems_exp_var(filename):
      
  
      assert os.path.exists(filename)
      import xml.etree.ElementTree as etree
      tree = etree.parse(filename)
      root = tree.getroot()
      dfs = {}
      for variogram in root:
          #print(variogram.tag)
          for attrib in variogram:
  
              #print(attrib.tag,attrib.text)
              if attrib.tag == "title":
                  title = attrib.text.split(',')[0].split('=')[-1]
              elif attrib.tag == "x":
                  x = [float(i) for i in attrib.text.split()]
              elif attrib.tag == "y":
                  y = [float(i) for i in attrib.text.split()]
              elif attrib.tag == "pairs":
                  pairs = [int(i) for i in attrib.text.split()]
  
              for item in attrib:
                  print(item,item.tag)
          df = pd.DataFrame({"x":x,"y":y,"pairs":pairs})
          df.loc[df.y<0.0,"y"] = np.NaN
          dfs[title] = df
      return dfs
docs: read an SGEM experimental variogram into a sequence of
      pandas.DataFrames
  
      Parameters
      ----------
      filename : (str)
          an SGEMS experimental variogram XML file
  
      Returns
      -------
      dfs : list
          a list of pandas.DataFrames of x, y, pairs for each
          division in the experimental variogram