code: def delete_columns(mat, columns_to_delete):
      """
      >>> a = csr_matrix(np.array([[0, 1, 3, 0, 1, 0],
                                         [0, 0, 1, 0, 1, 1]])
      >>> delete_columns(a, [1,2]).todense()
      matrix([[0, 0, 1, 0],
        [0, 0, 1, 1]])
  
      Parameters
      ----------
      mat : csr_matrix
      columns_to_delete : list[int]
  
      Returns
      -------
      csr_matrix that is stripped of columns indices columns_to_delete
      """
      column_mask = np.ones(mat.shape[1], dtype=bool)
      column_mask[columns_to_delete] = 0
      return mat.tocsc()[:, column_mask].tocsr()
  
file_path: scattertext/scattertext/CSRMatrixTools.py
imports: import numpy
  from scipy.sparse import csr_matrix
label_desc: Use image node_id 1 for calling a global function with example usage: delete_columns(mat, columns_to_delete) and returns: mat