code: def basen_to_integer(self, X, cols, base):
          
          out_cols = X.columns.values.tolist()
  
          for col in cols:
              col_list = [col0 for col0 in out_cols if str(col0).startswith(str(col))]
              insert_at = out_cols.index(col_list[0])
  
              if base == 1:
                  value_array = np.array([int(col0.split('_')[-1]) for col0 in col_list])
              else:
                  len0 = len(col_list)
                  value_array = np.array([base ** (len0 - 1 - i) for i in range(len0)])
              X.insert(insert_at, col, np.dot(X[col_list].values, value_array.T))
              X.drop(col_list, axis=1, inplace=True)
              out_cols = X.columns.values.tolist()
  
          return X
docs: Convert basen code as integers.
  
          Parameters
          ----------
          X : DataFrame
              encoded data
          cols : list-like
              Column names in the DataFrame that be encoded
          base : int
              The base of transform
  
          Returns
          -------
          numerical: DataFrame