code: def read(self, filename, rowprefix=None, colprefix=None, delim=":"):
          
  
          self.matrix = scipy.io.mmread(filename)
          with open(filename + ".rownames") as in_handle:
              self.rownames = [x.strip() for x in in_handle]
              if rowprefix:
                  self.rownames = [rowprefix + delim + x for x in self.rownames]
          with open(filename + ".colnames") as in_handle:
              self.colnames = [x.strip() for x in in_handle]
              if colprefix:
                  self.colnames = [colprefix + delim + x for x in self.colnames]
docs: read a sparse matrix, loading row and column name files. if
          specified, will add a prefix to the row or column names