code: def get_var_type(col):
      
      if pdtypes.is_numeric_dtype(col):
          # continuous
          return 'c'
      elif pdtypes.is_categorical_dtype(col):
          # ordered or unordered
          return 'o' if col.cat.ordered else 'u'
      else:
          # unordered if unsure, e.g string columns that
          # are not categorical
          return 'u'
docs: Return var_type (for KDEMultivariate) of the column
  
      Parameters
      ----------
      col : pandas.Series
          A dataframe column.
  
      Returns
      -------
      out : str
          One of ['c', 'o', 'u'].
  
      See Also
      --------
      The origin of the character codes is
      :class:`statsmodels.nonparametric.kernel_density.KDEMultivariate`.