parameters: (self, rows, col_slice)
return_statement: return new
docstring: Fast path for indexing in the case where column index is slice.
  
          This gains performance improvement over brute force by more
          efficient skipping of zeros, by accessing the elements
          column-wise in order.
  
          Parameters
          ----------
          rows : sequence or xrange
              Rows indexed. If xrange, must be within valid bounds.
          col_slice : slice
              Columns indexed
docstring_summary: Fast path for indexing in the case where column index is slice.
docstring_tokens: Fast path for indexing in the case where column index is slice .
function: def _get_row_ranges(self, rows, col_slice):
          """
          Fast path for indexing in the case where column index is slice.
  
          This gains performance improvement over brute force by more
          efficient skipping of zeros, by accessing the elements
          column-wise in order.
  
          Parameters
          ----------
          rows : sequence or xrange
              Rows indexed. If xrange, must be within valid bounds.
          col_slice : slice
              Columns indexed
  
          """
          j_start, j_stop, j_stride = col_slice.indices(self.shape[1])
          col_range = xrange(j_start, j_stop, j_stride)
          nj = len(col_range)
          new = lil_matrix((len(rows), nj), dtype=self.dtype)
  
          _csparsetools.lil_get_row_ranges(self.shape[0], self.shape[1],
                                           self.rows, self.data,
                                           new.rows, new.data,
                                           rows,
                                           j_start, j_stop, j_stride, nj)
  
          return new
function_tokens: def _get_row_ranges ( self , rows , col_slice ) : j_start , j_stop , j_stride = col_slice . indices ( self . shape [ 1 ] ) col_range = xrange ( j_start , j_stop , j_stride ) nj = len ( col_range ) new = lil_matrix ( ( len ( rows ) , nj ) , dtype = self . dtype ) _csparsetools . lil_get_row_ranges ( self . shape [ 0 ] , self . shape [ 1 ] , self . rows , self . data , new . rows , new . data , rows , j_start , j_stop , j_stride , nj ) return new