code: def pop_data_point(self, n):
          
  
          # loop over the columns and pop the data
          popped = []
          for k in self.ckeys:
  
              # first convert to a list
              data = list(self.c(k))
  
              # pop the data
              popped.append(data.pop(n))
  
              # now set this column again
              self.insert_column(_n.array(data), k)
  
          return popped
docs: This will remove and return the n'th data point (starting at 0) from
          all columns.
  
          Parameters
          ----------
          n       
              Index of data point to pop.