code: def get_column(self, column):
          
          if "(" in str(column):
              temp_list = column.split("(")
              key = temp_list[1].strip("()")
              func = temp_list[0].lower()
          else:
              key = column
              func = None
  
          if "." not in key:
              for i in self.columns:
                  if i.split(".")[1] == key:
                      key = i
                      break
  
          col = map(
              lambda x: x.get(
                  key
              ),
              self.rows
          )
  
          if func is not None:
              if func == "sum":
                  return [sum(col)]
              elif func == "max":
                  return [max(col)]
              elif func == "min":
                  return [min(col)]
              elif func == "avg":
                  return [sum(col) / float(len(col))]
              elif func == "count":
                  return [len(col)]
              elif func == "distinct":
                  return list(set(col))
              else:
                  raise Exception(
                      "Unknown function called on column"
                  )
  
          return col
docs: Return the values having of column.